21134221400 has 48 divisors (see below), whose sum is σ = 49438595400. Its totient is φ = 8401812480.

The previous prime is 21134221373. The next prime is 21134221421. The reversal of 21134221400 is 412243112.

It is a Harshad number since it is a multiple of its sum of digits (20).

It is a congruent number.

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, 291545 + ... + 356744.

Almost surely, 2^21134221400 is an apocalyptic number.

21134221400 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21134221400 is an abundant number, since it is smaller than the sum of its proper divisors (28304374000).

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

21134221400 is a wasteful number, since it uses less digits than its factorization.

21134221400 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 648468 (or 648459 counting only the distinct ones).

The product of its (nonzero) digits is 384, while the sum is 20.

Adding to 21134221400 its reverse (412243112), we get a palindrome (21546464512).

The spelling of 21134221400 in words is "twenty-one billion, one hundred thirty-four million, two hundred twenty-one thousand, four hundred".