66665525 has 12 divisors (see below), whose sum is σ = 82848864. Its totient is φ = 53214000.

The previous prime is 66665513. The next prime is 66665537. The reversal of 66665525 is 52556666.

It is an interprime number because it is at equal distance from previous prime (66665513) and next prime (66665537).

It is not a de Polignac number, because 66665525 - 2¹⁶ = 66599989 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 9560 + ... + 14990.

It is an arithmetic number, because the mean of its divisors is an integer number (6904072).

Almost surely, 2^66665525 is an apocalyptic number.

It is an amenable number.

66665525 is a deficient number, since it is larger than the sum of its proper divisors (16183339).

66665525 is a wasteful number, since it uses less digits than its factorization.

66665525 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5932 (or 5927 counting only the distinct ones).

The product of its digits is 324000, while the sum is 41.

The square root of 66665525 is about 8164.8958964582. The cubic root of 66665525 is about 405.4778184093.

The spelling of 66665525 in words is "sixty-six million, six hundred sixty-five thousand, five hundred twenty-five".