66201631 has 2 divisors, whose sum is σ = 66201632. Its totient is φ = 66201630.

The previous prime is 66201623. The next prime is 66201677. The reversal of 66201631 is 13610266.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 66201631 - 2³ = 66201623 is a prime.

It is a super-2 number, since 2×66201631² = 8765311894120322, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 66201596 and 66201605.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (66201601) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33100815 + 33100816.

It is an arithmetic number, because the mean of its divisors is an integer number (33100816).

Almost surely, 2^66201631 is an apocalyptic number.

66201631 is a deficient number, since it is larger than the sum of its proper divisors (1).

66201631 is an equidigital number, since it uses as much as digits as its factorization.

66201631 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1296, while the sum is 25.

The square root of 66201631 is about 8136.4384714690. The cubic root of 66201631 is about 404.5351186733.

Adding to 66201631 its reverse (13610266), we get a palindrome (79811897).

The spelling of 66201631 in words is "sixty-six million, two hundred one thousand, six hundred thirty-one".