66011631 has 8 divisors (see below), whose sum is σ = 100589184. Its totient is φ = 37720920.

The previous prime is 66011581. The next prime is 66011639. The reversal of 66011631 is 13611066.

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

It is not a de Polignac number, because 66011631 - 2¹¹ = 66009583 is a prime.

It is a super-2 number, since 2×66011631² = 8715070854560322, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66011639) 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, 1571685 + ... + 1571726.

It is an arithmetic number, because the mean of its divisors is an integer number (12573648).

Almost surely, 2^66011631 is an apocalyptic number.

66011631 is a deficient number, since it is larger than the sum of its proper divisors (34577553).

66011631 is a wasteful number, since it uses less digits than its factorization.

66011631 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3143421.

The product of its (nonzero) digits is 648, while the sum is 24.

The square root of 66011631 is about 8124.7542116670. The cubic root of 66011631 is about 404.1477398914.

Adding to 66011631 its reverse (13611066), we get a palindrome (79622697).

The spelling of 66011631 in words is "sixty-six million, eleven thousand, six hundred thirty-one".