Search a number
-
+
1243242021 = 37711674993
BaseRepresentation
bin100101000011010…
…0101111000100101
310012122101020102210
41022012211320211
510021232221041
6323210554033
742544245210
oct11206457045
93178336383
101243242021
1158886114a
122a8438919
1316a754888
14bb188777
157422d016
hex4a1a5e25

1243242021 has 32 divisors (see below), whose sum is σ = 1933037568. Its totient is φ = 696084480.

The previous prime is 1243242019. The next prime is 1243242031. The reversal of 1243242021 is 1202423421.

It is not a de Polignac number, because 1243242021 - 21 = 1243242019 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (21).

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1243242031) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 246501 + ... + 251493.

It is an arithmetic number, because the mean of its divisors is an integer number (60407424).

Almost surely, 21243242021 is an apocalyptic number.

It is an amenable number.

1243242021 is a deficient number, since it is larger than the sum of its proper divisors (689795547).

1243242021 is a wasteful number, since it uses less digits than its factorization.

1243242021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5241.

The product of its (nonzero) digits is 768, while the sum is 21.

The square root of 1243242021 is about 35259.6372783385. The cubic root of 1243242021 is about 1075.2725527775.

Adding to 1243242021 its reverse (1202423421), we get a palindrome (2445665442).

The spelling of 1243242021 in words is "one billion, two hundred forty-three million, two hundred forty-two thousand, twenty-one".

Divisors: 1 3 7 21 71 167 213 497 501 1169 1491 3507 4993 11857 14979 34951 35571 82999 104853 248997 354503 833831 1063509 2481521 2501493 5836817 7444563 17510451 59202001 177606003 414414007 1243242021