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102020021221 = 1491721397849
BaseRepresentation
bin101111100000011011…
…1011111101111100101
3100202022221200001102111
41133000313133233211
53132414111134341
6114511203041021
710241102605126
oct1370067375745
9322287601374
10102020021221
113a2a2707a28
1217932370171
13980b176a81
144d1b44c04d
1529c1754681
hex17c0ddfbe5

102020021221 has 8 divisors (see below), whose sum is σ = 102764655000. Its totient is φ = 101276186880.

The previous prime is 102020021179. The next prime is 102020021251. The reversal of 102020021221 is 122120020201.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 825412900 + 101194608321 = 28730^2 + 318111^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 102020021221 - 211 = 102020019173 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (102020021251) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 57505 + ... + 455353.

It is an arithmetic number, because the mean of its divisors is an integer number (12845581875).

Almost surely, 2102020021221 is an apocalyptic number.

It is an amenable number.

102020021221 is a deficient number, since it is larger than the sum of its proper divisors (744633779).

102020021221 is a wasteful number, since it uses less digits than its factorization.

102020021221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 399719.

The product of its (nonzero) digits is 32, while the sum is 13.

Adding to 102020021221 its reverse (122120020201), we get a palindrome (224140041422).

The spelling of 102020021221 in words is "one hundred two billion, twenty million, twenty-one thousand, two hundred twenty-one".

Divisors: 1 149 1721 256429 397849 59279501 684698129 102020021221