21198530957 has 16 divisors (see below), whose sum is σ = 22336376832. Its totient is φ = 20079362160.

The previous prime is 21198530939. The next prime is 21198530959. The reversal of 21198530957 is 75903589112.

It is a cyclic number.

It is not a de Polignac number, because 21198530957 - 2²⁴ = 21181753741 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21198530959) 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, 1460108 + ... + 1474554.

It is an arithmetic number, because the mean of its divisors is an integer number (1396023552).

Almost surely, 2^21198530957 is an apocalyptic number.

It is an amenable number.

21198530957 is a deficient number, since it is larger than the sum of its proper divisors (1137845875).

21198530957 is a wasteful number, since it uses less digits than its factorization.

21198530957 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15088.

The product of its (nonzero) digits is 680400, while the sum is 50.

The spelling of 21198530957 in words is "twenty-one billion, one hundred ninety-eight million, five hundred thirty thousand, nine hundred fifty-seven".