66615810085731 has 8 divisors (see below), whose sum is σ = 88839136869120. Its totient is φ = 44401511679752.

The previous prime is 66615810085663. The next prime is 66615810085763. The reversal of 66615810085731 is 13758001851666.

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

It is a cyclic number.

It is not a de Polignac number, because 66615810085731 - 2⁹ = 66615810085219 is a prime.

It is a super-2 number, since 2×66615810085731² (a number of 28 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (66615810085631) 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, 2257077135 + ... + 2257106648.

It is an arithmetic number, because the mean of its divisors is an integer number (11104892108640).

Almost surely, 2^{66615810085731} is an apocalyptic number.

66615810085731 is a deficient number, since it is larger than the sum of its proper divisors (22223326783389).

66615810085731 is a wasteful number, since it uses less digits than its factorization.

66615810085731 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4514188705.

The product of its (nonzero) digits is 7257600, while the sum is 57.

The spelling of 66615810085731 in words is "sixty-six trillion, six hundred fifteen billion, eight hundred ten million, eighty-five thousand, seven hundred thirty-one".