66921273 has 12 divisors (see below), whose sum is σ = 96762900. Its totient is φ = 44568576.

The previous prime is 66921269. The next prime is 66921301. The reversal of 66921273 is 37212966.

It can be written as a sum of positive squares in 2 ways, for example, as 60093504 + 6827769 = 7752^2 + 2613^2 .

It is not a de Polignac number, because 66921273 - 2² = 66921269 is a prime.

It is a hoax number, since the sum of its digits (36) coincides with the sum of the digits of its distinct prime factors.

It is not an unprimeable number, because it can be changed into a prime (66921203) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 7153 + ... + 13601.

It is an arithmetic number, because the mean of its divisors is an integer number (8063575).

Almost surely, 2^66921273 is an apocalyptic number.

It is an amenable number.

66921273 is a deficient number, since it is larger than the sum of its proper divisors (29841627).

66921273 is a wasteful number, since it uses less digits than its factorization.

66921273 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7608 (or 7605 counting only the distinct ones).

The product of its digits is 27216, while the sum is 36.

The square root of 66921273 is about 8180.5423414343. The cubic root of 66921273 is about 405.9956663535.

The spelling of 66921273 in words is "sixty-six million, nine hundred twenty-one thousand, two hundred seventy-three".