21768470 has 16 divisors (see below), whose sum is σ = 39389760. Its totient is φ = 8661504.

The previous prime is 21768457. The next prime is 21768497. The reversal of 21768470 is 7486712.

It is a happy number.

It is a super-2 number, since 2×21768470² = 947732572281800, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 21768470.

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, 3710 + ... + 7569.

It is an arithmetic number, because the mean of its divisors is an integer number (2461860).

Almost surely, 2^21768470 is an apocalyptic number.

21768470 is a deficient number, since it is larger than the sum of its proper divisors (17621290).

21768470 is a wasteful number, since it uses less digits than its factorization.

21768470 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11479.

The product of its (nonzero) digits is 18816, while the sum is 35.

The square root of 21768470 is about 4665.6692981822. The cubic root of 21768470 is about 279.2175006066.

The spelling of 21768470 in words is "twenty-one million, seven hundred sixty-eight thousand, four hundred seventy".