21022251600 has 120 divisors (see below), whose sum is σ = 76961492800. Its totient is φ = 4805084160.

The previous prime is 21022251539. The next prime is 21022251611. The reversal of 21022251600 is 615222012.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (120).

It is a Harshad number since it is a multiple of its sum of digits (21).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1242925 + ... + 1259724.

Almost surely, 2^21022251600 is an apocalyptic number.

21022251600 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21022251600 is an abundant number, since it is smaller than the sum of its proper divisors (55939241200).

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

21022251600 is a wasteful number, since it uses less digits than its factorization.

21022251600 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2502677 (or 2502666 counting only the distinct ones).

The product of its (nonzero) digits is 480, while the sum is 21.

Adding to 21022251600 its reverse (615222012), we get a palindrome (21637473612).

The spelling of 21022251600 in words is "twenty-one billion, twenty-two million, two hundred fifty-one thousand, six hundred".