21317703897 has 32 divisors (see below), whose sum is σ = 33017221120. Its totient is φ = 11983204800.

The previous prime is 21317703881. The next prime is 21317703917. The reversal of 21317703897 is 79830771312.

It is not a de Polignac number, because 21317703897 - 2⁴ = 21317703881 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21317703497) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 293979 + ... + 359247.

It is an arithmetic number, because the mean of its divisors is an integer number (1031788160).

Almost surely, 2^21317703897 is an apocalyptic number.

It is an amenable number.

21317703897 is a deficient number, since it is larger than the sum of its proper divisors (11699517223).

21317703897 is a wasteful number, since it uses less digits than its factorization.

21317703897 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 65533.

The product of its (nonzero) digits is 444528, while the sum is 48.

The spelling of 21317703897 in words is "twenty-one billion, three hundred seventeen million, seven hundred three thousand, eight hundred ninety-seven".