66051631 has 4 divisors (see below), whose sum is σ = 66114832. Its totient is φ = 65988432.

The previous prime is 66051611. The next prime is 66051637. The reversal of 66051631 is 13615066.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 66051631 - 2⁵ = 66051599 is a prime.

It is a super-2 number, since 2×66051631² = 8725635915520322, 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 66051631.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66051637) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 30006 + ... + 32131.

It is an arithmetic number, because the mean of its divisors is an integer number (16528708).

Almost surely, 2^66051631 is an apocalyptic number.

66051631 is a deficient number, since it is larger than the sum of its proper divisors (63201).

66051631 is a wasteful number, since it uses less digits than its factorization.

66051631 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 63200.

The product of its (nonzero) digits is 3240, while the sum is 28.

The square root of 66051631 is about 8127.2154518014. The cubic root of 66051631 is about 404.2293550310.

Adding to 66051631 its reverse (13615066), we get a palindrome (79666697).

The spelling of 66051631 in words is "sixty-six million, fifty-one thousand, six hundred thirty-one".