66401017631 has 8 divisors (see below), whose sum is σ = 71903866944. Its totient is φ = 60954608160.

The previous prime is 66401017601. The next prime is 66401017649. The reversal of 66401017631 is 13671010466.

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 66401017631 - 2¹⁰ = 66401016607 is a prime.

It is a super-2 number, since 2×66401017631² (a number of 22 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 66401017591 and 66401017600.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66401017601) 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, 14107511 + ... + 14112216.

It is an arithmetic number, because the mean of its divisors is an integer number (8987983368).

Almost surely, 2^66401017631 is an apocalyptic number.

66401017631 is a deficient number, since it is larger than the sum of its proper divisors (5502849313).

66401017631 is a wasteful number, since it uses less digits than its factorization.

66401017631 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 28219921.

The product of its (nonzero) digits is 18144, while the sum is 35.

The spelling of 66401017631 in words is "sixty-six billion, four hundred one million, seventeen thousand, six hundred thirty-one".