666051615 has 24 divisors (see below), whose sum is σ = 1185694848. Its totient is φ = 345625920.

The previous prime is 666051599. The next prime is 666051643. The reversal of 666051615 is 516150666.

It is not a de Polignac number, because 666051615 - 2⁴ = 666051599 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 666051615.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 198351 + ... + 201680.

It is an arithmetic number, because the mean of its divisors is an integer number (49403952).

Almost surely, 2^666051615 is an apocalyptic number.

666051615 is a deficient number, since it is larger than the sum of its proper divisors (519643233).

666051615 is a wasteful number, since it uses less digits than its factorization.

666051615 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 400079 (or 400076 counting only the distinct ones).

The product of its (nonzero) digits is 32400, while the sum is 36.

The square root of 666051615 is about 25807.9758020655. The cubic root of 666051615 is about 873.3117335172.

It can be divided in two parts, 666051 and 615, that added together give a palindrome (666666).

The spelling of 666051615 in words is "six hundred sixty-six million, fifty-one thousand, six hundred fifteen".