21490776 has 24 divisors (see below), whose sum is σ = 58204380. Its totient is φ = 7163568.

The previous prime is 21490759. The next prime is 21490783. The reversal of 21490776 is 67709412.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (24).

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

It is a self number, because there is not a number n which added to its sum of digits gives 21490776.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 149170 + ... + 149313.

Almost surely, 2^21490776 is an apocalyptic number.

It is an amenable number.

21490776 is an abundant number, since it is smaller than the sum of its proper divisors (36713604).

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

21490776 is a wasteful number, since it uses less digits than its factorization.

21490776 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 298495 (or 298488 counting only the distinct ones).

The product of its (nonzero) digits is 21168, while the sum is 36.

The square root of 21490776 is about 4635.8144915430. The cubic root of 21490776 is about 278.0251172034.

The spelling of 21490776 in words is "twenty-one million, four hundred ninety thousand, seven hundred seventy-six".