21901975738 has 8 divisors (see below), whose sum is σ = 34785490932. Its totient is φ = 10306812096.

The previous prime is 21901975727. The next prime is 21901975759. The reversal of 21901975738 is 83757910912.

It can be written as a sum of positive squares in 2 ways, for example, as 21474850849 + 427124889 = 146543^2 + 20667^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 322087845 + ... + 322087912.

Almost surely, 2^21901975738 is an apocalyptic number.

21901975738 is a deficient number, since it is larger than the sum of its proper divisors (12883515194).

21901975738 is a wasteful number, since it uses less digits than its factorization.

21901975738 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 644175776.

The product of its (nonzero) digits is 952560, while the sum is 52.

The spelling of 21901975738 in words is "twenty-one billion, nine hundred one million, nine hundred seventy-five thousand, seven hundred thirty-eight".