21192012 has 18 divisors (see below), whose sum is σ = 53568788. Its totient is φ = 7063992.

The previous prime is 21192007. The next prime is 21192029. The reversal of 21192012 is 21029112.

It is a tau number, because it is divible by the number of its divisors (18).

It is a Harshad number since it is a multiple of its sum of digits (18).

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 294298 + ... + 294369.

Almost surely, 2^21192012 is an apocalyptic number.

It is an amenable number.

21192012 is an abundant number, since it is smaller than the sum of its proper divisors (32376776).

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

21192012 is a wasteful number, since it uses less digits than its factorization.

21192012 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 588677 (or 588672 counting only the distinct ones).

The product of its (nonzero) digits is 72, while the sum is 18.

The square root of 21192012 is about 4603.4782501930. The cubic root of 21192012 is about 276.7307353115.

The spelling of 21192012 in words is "twenty-one million, one hundred ninety-two thousand, twelve".