516400665 has 16 divisors (see below), whose sum is σ = 901354176. Its totient is φ = 250376000.

The previous prime is 516400649. The next prime is 516400667. The reversal of 516400665 is 566004615.

It is not a de Polignac number, because 516400665 - 2⁴ = 516400649 is a prime.

It is a Smith number, since the sum of its digits (33) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Harshad number since it is a multiple of its sum of digits (33).

It is not an unprimeable number, because it can be changed into a prime (516400667) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1564686 + ... + 1565015.

It is an arithmetic number, because the mean of its divisors is an integer number (56334636).

Almost surely, 2^516400665 is an apocalyptic number.

516400665 is a gapful number since it is divisible by the number (55) formed by its first and last digit.

It is an amenable number.

516400665 is a deficient number, since it is larger than the sum of its proper divisors (384953511).

516400665 is a wasteful number, since it uses less digits than its factorization.

516400665 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3129720.

The product of its (nonzero) digits is 21600, while the sum is 33.

The square root of 516400665 is about 22724.4508184466. The cubic root of 516400665 is about 802.2854775436.

The spelling of 516400665 in words is "five hundred sixteen million, four hundred thousand, six hundred sixty-five".