66513775 has 24 divisors (see below), whose sum is σ = 91936080. Its totient is φ = 47439360.

The previous prime is 66513763. The next prime is 66513787. The reversal of 66513775 is 57731566.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (66513763) and next prime (66513787).

It is not a de Polignac number, because 66513775 - 2⁵ = 66513743 is a prime.

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, 3957 + ... + 12193.

It is an arithmetic number, because the mean of its divisors is an integer number (3830670).

Almost surely, 2^66513775 is an apocalyptic number.

66513775 is a deficient number, since it is larger than the sum of its proper divisors (25422305).

66513775 is a wasteful number, since it uses less digits than its factorization.

66513775 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8283 (or 8278 counting only the distinct ones).

The product of its digits is 132300, while the sum is 40.

The square root of 66513775 is about 8155.5977708565. The cubic root of 66513775 is about 405.1699231080.

The spelling of 66513775 in words is "sixty-six million, five hundred thirteen thousand, seven hundred seventy-five".