21225225400 has 24 divisors (see below), whose sum is σ = 49348649520. Its totient is φ = 8490090080.

The previous prime is 21225225379. The next prime is 21225225419. The reversal of 21225225400 is 452252212.

It is a Harshad number since it is a multiple of its sum of digits (25).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 53062864 + ... + 53063263.

It is an arithmetic number, because the mean of its divisors is an integer number (2056193730).

Almost surely, 2^21225225400 is an apocalyptic number.

21225225400 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21225225400 is an abundant number, since it is smaller than the sum of its proper divisors (28123424120).

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

21225225400 is a wasteful number, since it uses less digits than its factorization.

21225225400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 106126143 (or 106126134 counting only the distinct ones).

The product of its (nonzero) digits is 3200, while the sum is 25.

Adding to 21225225400 its reverse (452252212), we get a palindrome (21677477612).

The spelling of 21225225400 in words is "twenty-one billion, two hundred twenty-five million, two hundred twenty-five thousand, four hundred".