66400995 has 16 divisors (see below), whose sum is σ = 107009280. Its totient is φ = 35157984.

The previous prime is 66400993. The next prime is 66401003. The reversal of 66400995 is 59900466.

It is not a de Polignac number, because 66400995 - 2¹ = 66400993 is a prime.

It is not an unprimeable number, because it can be changed into a prime (66400993) 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, 13839 + ... + 18008.

It is an arithmetic number, because the mean of its divisors is an integer number (6688080).

Almost surely, 2^66400995 is an apocalyptic number.

66400995 is a deficient number, since it is larger than the sum of its proper divisors (40608285).

66400995 is a wasteful number, since it uses less digits than its factorization.

66400995 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 31994.

The product of its (nonzero) digits is 58320, while the sum is 39.

The square root of 66400995 is about 8148.6805680429. The cubic root of 66400995 is about 404.9407930520.

The spelling of 66400995 in words is "sixty-six million, four hundred thousand, nine hundred ninety-five".