21187692 has 36 divisors (see below), whose sum is σ = 55888560. Its totient is φ = 6755232.

The previous prime is 21187687. The next prime is 21187697. The reversal of 21187692 is 29678112.

It is an interprime number because it is at equal distance from previous prime (21187687) and next prime (21187697).

It is a tau number, because it is divible by the number of its divisors (36).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is not an unprimeable number, because it can be changed into a prime (21187697) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 11967 + ... + 13622.

It is an arithmetic number, because the mean of its divisors is an integer number (1552460).

Almost surely, 2^21187692 is an apocalyptic number.

It is an amenable number.

21187692 is an abundant number, since it is smaller than the sum of its proper divisors (34700868).

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

21187692 is a wasteful number, since it uses less digits than its factorization.

21187692 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 25622 (or 25617 counting only the distinct ones).

The product of its digits is 12096, while the sum is 36.

The square root of 21187692 is about 4603.0090158504. The cubic root of 21187692 is about 276.7119301438.

The spelling of 21187692 in words is "twenty-one million, one hundred eighty-seven thousand, six hundred ninety-two".