21074656 has 24 divisors (see below), whose sum is σ = 42505344. Its totient is φ = 10279680.

The previous prime is 21074639. The next prime is 21074657. The reversal of 21074656 is 65647012.

It is a happy number.

It is a super-2 number, since 2×21074656² = 888282251036672, which contains 22 as substring.

It is a Smith number, since the sum of its digits (31) coincides with the sum of the digits of its prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21074657) 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, 6720 + ... + 9343.

It is an arithmetic number, because the mean of its divisors is an integer number (1771056).

Almost surely, 2^21074656 is an apocalyptic number.

It is an amenable number.

21074656 is an abundant number, since it is smaller than the sum of its proper divisors (21430688).

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

21074656 is a wasteful number, since it uses less digits than its factorization.

21074656 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16114 (or 16106 counting only the distinct ones).

The product of its (nonzero) digits is 10080, while the sum is 31.

The square root of 21074656 is about 4590.7141056703. The cubic root of 21074656 is about 276.2189678702.

The spelling of 21074656 in words is "twenty-one million, seventy-four thousand, six hundred fifty-six".