66213757 has 16 divisors (see below), whose sum is σ = 73434240. Its totient is φ = 59476032.

The previous prime is 66213751. The next prime is 66213769. The reversal of 66213757 is 75731266.

It is a cyclic number.

It is not a de Polignac number, because 66213757 - 2⁷ = 66213629 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (37).

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66213751) 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, 23338 + ... + 26020.

It is an arithmetic number, because the mean of its divisors is an integer number (4589640).

Almost surely, 2^66213757 is an apocalyptic number.

It is an amenable number.

66213757 is a deficient number, since it is larger than the sum of its proper divisors (7220483).

66213757 is a wasteful number, since it uses less digits than its factorization.

66213757 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2772.

The product of its digits is 52920, while the sum is 37.

The square root of 66213757 is about 8137.1836036801. The cubic root of 66213757 is about 404.5598164202.

The spelling of 66213757 in words is "sixty-six million, two hundred thirteen thousand, seven hundred fifty-seven".