21012320097 has 6 divisors (see below), whose sum is σ = 30351129042. Its totient is φ = 14008213392.

The previous prime is 21012320081. The next prime is 21012320099. The reversal of 21012320097 is 79002321012.

It can be written as a sum of positive squares in only one way, i.e., 21010792401 + 1527696 = 144951^2 + 1236^2 .

It is not a de Polignac number, because 21012320097 - 2⁴ = 21012320081 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21012320097.

It is not an unprimeable number, because it can be changed into a prime (21012320099) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1167351108 + ... + 1167351125.

It is an arithmetic number, because the mean of its divisors is an integer number (5058521507).

Almost surely, 2^21012320097 is an apocalyptic number.

It is an amenable number.

21012320097 is a deficient number, since it is larger than the sum of its proper divisors (9338808945).

21012320097 is a wasteful number, since it uses less digits than its factorization.

21012320097 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2334702239 (or 2334702236 counting only the distinct ones).

The product of its (nonzero) digits is 1512, while the sum is 27.

The spelling of 21012320097 in words is "twenty-one billion, twelve million, three hundred twenty thousand, ninety-seven".