21154720352 has 12 divisors (see below), whose sum is σ = 41648355756. Its totient is φ = 10577360160.

The previous prime is 21154720339. The next prime is 21154720357. The reversal of 21154720352 is 25302745112.

It is a Harshad number since it is a multiple of its sum of digits (32), and also a Moran number because the ratio is a prime number: 661085011 = 21154720352 / (2 + 1 + 1 + 5 + 4 + 7 + 2 + 0 + 3 + 5 + 2).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21154720357) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 330542474 + ... + 330542537.

It is an arithmetic number, because the mean of its divisors is an integer number (3470696313).

Almost surely, 2^21154720352 is an apocalyptic number.

It is an amenable number.

21154720352 is a deficient number, since it is larger than the sum of its proper divisors (20493635404).

21154720352 is an equidigital number, since it uses as much as digits as its factorization.

21154720352 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 661085021 (or 661085013 counting only the distinct ones).

The product of its (nonzero) digits is 16800, while the sum is 32.

The spelling of 21154720352 in words is "twenty-one billion, one hundred fifty-four million, seven hundred twenty thousand, three hundred fifty-two".