66315555 has 48 divisors (see below), whose sum is σ = 127033920. Its totient is φ = 31832064.

The previous prime is 66315539. The next prime is 66315563. The reversal of 66315555 is 55551366.

It is not a de Polignac number, because 66315555 - 2⁴ = 66315539 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 15711 + ... + 19479.

It is an arithmetic number, because the mean of its divisors is an integer number (2646540).

Almost surely, 2^66315555 is an apocalyptic number.

66315555 is a deficient number, since it is larger than the sum of its proper divisors (60718365).

66315555 is a wasteful number, since it uses less digits than its factorization.

66315555 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3820 (or 3817 counting only the distinct ones).

The product of its digits is 67500, while the sum is 36.

The square root of 66315555 is about 8143.4363139893. The cubic root of 66315555 is about 404.7670356586.

The spelling of 66315555 in words is "sixty-six million, three hundred fifteen thousand, five hundred fifty-five".