21250000400 has 30 divisors (see below), whose sum is σ = 51053126922. Its totient is φ = 8500000000.

The previous prime is 21250000339. The next prime is 21250000411. The reversal of 21250000400 is 400005212.

It can be written as a sum of positive squares in 3 ways, for example, as 176252176 + 21073748224 = 13276^2 + 145168^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 26562101 + ... + 26562900.

Almost surely, 2^21250000400 is an apocalyptic number.

21250000400 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21250000400 is an abundant number, since it is smaller than the sum of its proper divisors (29803126522).

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

21250000400 is a wasteful number, since it uses less digits than its factorization.

21250000400 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 53125019 (or 53125008 counting only the distinct ones).

The product of its (nonzero) digits is 80, while the sum is 14.

Adding to 21250000400 its reverse (400005212), we get a palindrome (21650005612).

The spelling of 21250000400 in words is "twenty-one billion, two hundred fifty million, four hundred", and thus it is an aban number.