21139490985 has 32 divisors (see below), whose sum is σ = 35185104000. Its totient is φ = 10824769536.

The previous prime is 21139490951. The next prime is 21139490987. The reversal of 21139490985 is 58909493112.

It is not a de Polignac number, because 21139490985 - 2⁷ = 21139490857 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21139490987) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 57880 + ... + 213609.

It is an arithmetic number, because the mean of its divisors is an integer number (1099534500).

Almost surely, 2^21139490985 is an apocalyptic number.

It is an amenable number.

21139490985 is a deficient number, since it is larger than the sum of its proper divisors (14045613015).

21139490985 is a wasteful number, since it uses less digits than its factorization.

21139490985 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 271705.

The product of its (nonzero) digits is 699840, while the sum is 51.

The spelling of 21139490985 in words is "twenty-one billion, one hundred thirty-nine million, four hundred ninety thousand, nine hundred eighty-five".