21451901000 has 32 divisors (see below), whose sum is σ = 50197450680. Its totient is φ = 8580760000.

The previous prime is 21451900973. The next prime is 21451901011. The reversal of 21451901000 is 10915412.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 5158399684 + 16293501316 = 71822^2 + 127646^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 10724951 + ... + 10726950.

Almost surely, 2^21451901000 is an apocalyptic number.

21451901000 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21451901000 is an abundant number, since it is smaller than the sum of its proper divisors (28745549680).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21451901000 is a wasteful number, since it uses less digits than its factorization.

21451901000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21451922 (or 21451908 counting only the distinct ones).

The product of its (nonzero) digits is 360, while the sum is 23.

The spelling of 21451901000 in words is "twenty-one billion, four hundred fifty-one million, nine hundred one thousand".