21550214925 has 36 divisors (see below), whose sum is σ = 38607064704. Its totient is φ = 11490996000.

The previous prime is 21550214921. The next prime is 21550214957. The reversal of 21550214925 is 52941205512.

21550214925 is a `hidden beast` number, since 2 + 1 + 5 + 502 + 149 + 2 + 5 = 666.

It is not a de Polignac number, because 21550214925 - 2² = 21550214921 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21550214925.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21550214921) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 1632100 + ... + 1645250.

It is an arithmetic number, because the mean of its divisors is an integer number (1072418464).

Almost surely, 2^21550214925 is an apocalyptic number.

21550214925 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21550214925 is a deficient number, since it is larger than the sum of its proper divisors (17056849779).

21550214925 is a wasteful number, since it uses less digits than its factorization.

21550214925 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20450 (or 20442 counting only the distinct ones).

The product of its (nonzero) digits is 36000, while the sum is 36.

The spelling of 21550214925 in words is "twenty-one billion, five hundred fifty million, two hundred fourteen thousand, nine hundred twenty-five".