66128895 has 96 divisors (see below), whose sum is σ = 141927552. Its totient is φ = 27795456.

The previous prime is 66128891. The next prime is 66128899. The reversal of 66128895 is 59882166.

It is an interprime number because it is at equal distance from previous prime (66128891) and next prime (66128899).

It is not a de Polignac number, because 66128895 - 2² = 66128891 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a self number, because there is not a number n which added to its sum of digits gives 66128895.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66128891) by changing a digit.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 283699 + ... + 283931.

It is an arithmetic number, because the mean of its divisors is an integer number (1478412).

Almost surely, 2^66128895 is an apocalyptic number.

66128895 is an abundant number, since it is smaller than the sum of its proper divisors (75798657).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

66128895 is a wasteful number, since it uses less digits than its factorization.

66128895 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 321 (or 318 counting only the distinct ones).

The product of its digits is 207360, while the sum is 45.

The square root of 66128895 is about 8131.9674741110. The cubic root of 66128895 is about 404.3869095899.

The spelling of 66128895 in words is "sixty-six million, one hundred twenty-eight thousand, eight hundred ninety-five".