21253470400 has 84 divisors (see below), whose sum is σ = 52815012480. Its totient is φ = 8417152000.

The previous prime is 21253470361. The next prime is 21253470487. The reversal of 21253470400 is 407435212.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 95841 + ... + 227359.

Almost surely, 2^21253470400 is an apocalyptic number.

21253470400 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21253470400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (26407506240).

21253470400 is an abundant number, since it is smaller than the sum of its proper divisors (31561542080).

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

21253470400 is a wasteful number, since it uses less digits than its factorization.

21253470400 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 131642 (or 131627 counting only the distinct ones).

The product of its (nonzero) digits is 6720, while the sum is 28.

The spelling of 21253470400 in words is "twenty-one billion, two hundred fifty-three million, four hundred seventy thousand, four hundred".