66457731 has 8 divisors (see below), whose sum is σ = 90063184. Its totient is φ = 43578720.

The previous prime is 66457693. The next prime is 66457751. The reversal of 66457731 is 13775466.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a de Polignac number, because none of the positive numbers 2^k-66457731 is a prime.

It is a super-2 number, since 2×66457731² = 8833260019336722, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 66457731.

It is not an unprimeable number, because it can be changed into a prime (66457751) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 181396 + ... + 181761.

It is an arithmetic number, because the mean of its divisors is an integer number (11257898).

Almost surely, 2^66457731 is an apocalyptic number.

66457731 is a gapful number since it is divisible by the number (61) formed by its first and last digit.

66457731 is a deficient number, since it is larger than the sum of its proper divisors (23605453).

66457731 is a wasteful number, since it uses less digits than its factorization.

66457731 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 363221.

The product of its digits is 105840, while the sum is 39.

The square root of 66457731 is about 8152.1611245117. The cubic root of 66457731 is about 405.0560934347.

The spelling of 66457731 in words is "sixty-six million, four hundred fifty-seven thousand, seven hundred thirty-one".