21031900986 has 16 divisors (see below), whose sum is σ = 42306947424. Its totient is φ = 6970109424.

The previous prime is 21031900979. The next prime is 21031900987. The reversal of 21031900986 is 68900913012.

It is not an unprimeable number, because it can be changed into a prime (21031900987) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 10129936 + ... + 10132011.

It is an arithmetic number, because the mean of its divisors is an integer number (2644184214).

Almost surely, 2^21031900986 is an apocalyptic number.

21031900986 is an abundant number, since it is smaller than the sum of its proper divisors (21275046438).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21031900986 is a wasteful number, since it uses less digits than its factorization.

21031900986 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20262125.

The product of its (nonzero) digits is 23328, while the sum is 39.

The spelling of 21031900986 in words is "twenty-one billion, thirty-one million, nine hundred thousand, nine hundred eighty-six".