21360690 has 48 divisors (see below), whose sum is σ = 59813208. Its totient is φ = 5257728.

The previous prime is 21360683. The next prime is 21360697. The reversal of 21360690 is 9606312.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (21360683) and next prime (21360697).

It can be written as a sum of positive squares in 4 ways, for example, as 11229201 + 10131489 = 3351^2 + 3183^2 .

It is a super-2 number, since 2×21360690² = 912558154552200, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21360697) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 7959 + ... + 10298.

Almost surely, 2^21360690 is an apocalyptic number.

21360690 is an abundant number, since it is smaller than the sum of its proper divisors (38452518).

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

21360690 is a wasteful number, since it uses less digits than its factorization.

21360690 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18283 (or 18280 counting only the distinct ones).

The product of its (nonzero) digits is 1944, while the sum is 27.

The square root of 21360690 is about 4621.7626507643. The cubic root of 21360690 is about 277.4630094351.

The spelling of 21360690 in words is "twenty-one million, three hundred sixty thousand, six hundred ninety".