21253973745 has 32 divisors (see below), whose sum is σ = 35581796352. Its totient is φ = 10812998592.

The previous prime is 21253973711. The next prime is 21253973771. The reversal of 21253973745 is 54737935212.

It is not a de Polignac number, because 21253973745 - 2⁶ = 21253973681 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21253973694 and 21253973703.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 42684 + ... + 210546.

It is an arithmetic number, because the mean of its divisors is an integer number (1111931136).

Almost surely, 2^21253973745 is an apocalyptic number.

It is an amenable number.

21253973745 is a deficient number, since it is larger than the sum of its proper divisors (14327822607).

21253973745 is a wasteful number, since it uses less digits than its factorization.

21253973745 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 168261.

The product of its digits is 1587600, while the sum is 48.

The spelling of 21253973745 in words is "twenty-one billion, two hundred fifty-three million, nine hundred seventy-three thousand, seven hundred forty-five".