21354765 has 16 divisors (see below), whose sum is σ = 35966400. Its totient is φ = 10789632.

The previous prime is 21354721. The next prime is 21354797. The reversal of 21354765 is 56745312.

It is not a de Polignac number, because 21354765 - 2¹³ = 21346573 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 37180 + ... + 37749.

It is an arithmetic number, because the mean of its divisors is an integer number (2247900).

Almost surely, 2^21354765 is an apocalyptic number.

It is an amenable number.

21354765 is a deficient number, since it is larger than the sum of its proper divisors (14611635).

21354765 is a wasteful number, since it uses less digits than its factorization.

21354765 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 74956.

The product of its digits is 25200, while the sum is 33.

The square root of 21354765 is about 4621.1216170969. The cubic root of 21354765 is about 277.4373529550.

The spelling of 21354765 in words is "twenty-one million, three hundred fifty-four thousand, seven hundred sixty-five".