21474765 has 24 divisors (see below), whose sum is σ = 40087320. Its totient is φ = 10571904.

The previous prime is 21474751. The next prime is 21474781. The reversal of 21474765 is 56747412.

It can be written as a sum of positive squares in 4 ways, for example, as 213444 + 21261321 = 462^2 + 4611^2 .

It is not a de Polignac number, because 21474765 - 2⁷ = 21474637 is a prime.

It is a super-2 number, since 2×21474765² = 922331063610450, which contains 22 as substring.

It is an alternating number because its digits alternate between even and odd.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 17770 + ... + 18939.

It is an arithmetic number, because the mean of its divisors is an integer number (1670305).

Almost surely, 2^21474765 is an apocalyptic number.

It is an amenable number.

21474765 is a deficient number, since it is larger than the sum of its proper divisors (18612555).

21474765 is a wasteful number, since it uses less digits than its factorization.

21474765 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 36733 (or 36730 counting only the distinct ones).

The product of its digits is 47040, while the sum is 36.

The square root of 21474765 is about 4634.0872887765. The cubic root of 21474765 is about 277.9560555420.

The spelling of 21474765 in words is "twenty-one million, four hundred seventy-four thousand, seven hundred sixty-five".