21373065 has 72 divisors (see below), whose sum is σ = 44815680. Its totient is φ = 9743328.

The previous prime is 21373061. The next prime is 21373069. The reversal of 21373065 is 56037312.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (21373061) and next prime (21373069).

It is not a de Polignac number, because 21373065 - 2² = 21373061 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is not an unprimeable number, because it can be changed into a prime (21373061) by changing a digit.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 59356 + ... + 59714.

It is an arithmetic number, because the mean of its divisors is an integer number (622440).

Almost surely, 2^21373065 is an apocalyptic number.

It is an amenable number.

21373065 is an abundant number, since it is smaller than the sum of its proper divisors (23442615).

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

21373065 is an equidigital number, since it uses as much as digits as its factorization.

21373065 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 393 (or 374 counting only the distinct ones).

The product of its (nonzero) digits is 3780, while the sum is 27.

The square root of 21373065 is about 4623.1012318572. The cubic root of 21373065 is about 277.5165804556.

The spelling of 21373065 in words is "twenty-one million, three hundred seventy-three thousand, sixty-five".