21187133902 has 16 divisors (see below), whose sum is σ = 34942851072. Its totient is φ = 9554683320.

The previous prime is 21187133897. The next prime is 21187133911. The reversal of 21187133902 is 20933178112.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3788748 + ... + 3794335.

It is an arithmetic number, because the mean of its divisors is an integer number (2183928192).

Almost surely, 2^21187133902 is an apocalyptic number.

21187133902 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

21187133902 is a deficient number, since it is larger than the sum of its proper divisors (13755717170).

21187133902 is a wasteful number, since it uses less digits than its factorization.

21187133902 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7583223.

The product of its (nonzero) digits is 18144, while the sum is 37.

The spelling of 21187133902 in words is "twenty-one billion, one hundred eighty-seven million, one hundred thirty-three thousand, nine hundred two".