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121200021 = 32171316047
BaseRepresentation
bin1110011100101…
…01110110010101
322110001121011200
413032111312111
5222011400041
620005423113
73001116555
oct716256625
9273047150
10121200021
1162461408
123470aa99
131c1571b7
141214d165
15a9911b6
hex7395d95

121200021 has 24 divisors (see below), whose sum is σ = 186810624. Its totient is φ = 75454080.

The previous prime is 121200017. The next prime is 121200047. The reversal of 121200021 is 120002121.

It is not a de Polignac number, because 121200021 - 22 = 121200017 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (9).

It is a junction number, because it is equal to n+sod(n) for n = 121199976 and 121200012.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (121200011) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 17020 + ... + 23066.

It is an arithmetic number, because the mean of its divisors is an integer number (7783776).

Almost surely, 2121200021 is an apocalyptic number.

It is an amenable number.

121200021 is a deficient number, since it is larger than the sum of its proper divisors (65610603).

121200021 is a wasteful number, since it uses less digits than its factorization.

121200021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6201 (or 6198 counting only the distinct ones).

The product of its (nonzero) digits is 8, while the sum is 9.

The square root of 121200021 is about 11009.0881093758. The cubic root of 121200021 is about 494.8811346055.

Adding to 121200021 its reverse (120002121), we get a palindrome (241202142).

The spelling of 121200021 in words is "one hundred twenty-one million, two hundred thousand, twenty-one".

Divisors: 1 3 9 17 51 131 153 393 1179 2227 6047 6681 18141 20043 54423 102799 308397 792157 925191 2376471 7129413 13466669 40400007 121200021