21097853001 has 15 divisors (see below), whose sum is σ = 31518498781. Its totient is φ = 14064363828.

The previous prime is 21097852981. The next prime is 21097853027. The reversal of 21097853001 is 10035879012.

The square root of 21097853001 is 145251.

It is a perfect power (a square), and thus also a powerful number.

It is not a de Polignac number, because 21097853001 - 2⁵ = 21097852969 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21097853041) by changing a digit.

It is a polite number, since it can be written in 14 ways as a sum of consecutive naturals, for example, 1299190 + ... + 1315328.

Almost surely, 2^21097853001 is an apocalyptic number.

21097853001 is the 145251-st square number.

21097853001 is the 72626-th centered octagonal number.

It is an amenable number.

21097853001 is a deficient number, since it is larger than the sum of its proper divisors (10420645780).

21097853001 is an frugal number, since it uses more digits than its factorization.

21097853001 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 32290 (or 16142 counting only the distinct ones).

The product of its (nonzero) digits is 15120, while the sum is 36.

Multiplying 21097853001 by its sum of digits (36), we get a square (759522708036 = 871506²).

The spelling of 21097853001 in words is "twenty-one billion, ninety-seven million, eight hundred fifty-three thousand, one".