21128531037 has 16 divisors (see below), whose sum is σ = 28778725440. Its totient is φ = 13783416192.

The previous prime is 21128531033. The next prime is 21128531051. The reversal of 21128531037 is 73013582112.

It is a happy number.

It is not a de Polignac number, because 21128531037 - 2² = 21128531033 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21128530989 and 21128531007.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21128531033) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 115048 + ... + 235569.

It is an arithmetic number, because the mean of its divisors is an integer number (1798670340).

Almost surely, 2^21128531037 is an apocalyptic number.

It is an amenable number.

21128531037 is a deficient number, since it is larger than the sum of its proper divisors (7650194403).

21128531037 is a wasteful number, since it uses less digits than its factorization.

21128531037 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 351052.

The product of its (nonzero) digits is 10080, while the sum is 33.

The spelling of 21128531037 in words is "twenty-one billion, one hundred twenty-eight million, five hundred thirty-one thousand, thirty-seven".