21006892 has 12 divisors (see below), whose sum is σ = 36953896. Its totient is φ = 10448640.

The previous prime is 21006877. The next prime is 21006893. The reversal of 21006892 is 29860012.

It is a happy number.

It is a super-2 number, since 2×21006892² = 882579022999328, which contains 22 as substring.

It is a hoax number, since the sum of its digits (28) coincides with the sum of the digits of its distinct prime factors.

It is a self number, because there is not a number n which added to its sum of digits gives 21006892.

It is not an unprimeable number, because it can be changed into a prime (21006893) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 12834 + ... + 14377.

Almost surely, 2^21006892 is an apocalyptic number.

It is an amenable number.

21006892 is a deficient number, since it is larger than the sum of its proper divisors (15947004).

21006892 is a wasteful number, since it uses less digits than its factorization.

21006892 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 27408 (or 27406 counting only the distinct ones).

The product of its (nonzero) digits is 1728, while the sum is 28.

The square root of 21006892 is about 4583.3276121176. The cubic root of 21006892 is about 275.9225960916.

The spelling of 21006892 in words is "twenty-one million, six thousand, eight hundred ninety-two".