521423665 has 8 divisors (see below), whose sum is σ = 715095360. Its totient is φ = 357547632.

The previous prime is 521423659. The next prime is 521423717. The reversal of 521423665 is 566324125.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 521423665 - 2¹⁵ = 521390897 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 521423665.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 7448875 + ... + 7448944.

It is an arithmetic number, because the mean of its divisors is an integer number (89386920).

Almost surely, 2^521423665 is an apocalyptic number.

It is an amenable number.

521423665 is a deficient number, since it is larger than the sum of its proper divisors (193671695).

521423665 is a wasteful number, since it uses less digits than its factorization.

521423665 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14897831.

The product of its digits is 43200, while the sum is 34.

The square root of 521423665 is about 22834.7030854356. The cubic root of 521423665 is about 804.8783505077.

The spelling of 521423665 in words is "five hundred twenty-one million, four hundred twenty-three thousand, six hundred sixty-five".