266720631 has 4 divisors (see below), whose sum is σ = 355627512. Its totient is φ = 177813752.

The previous prime is 266720603. The next prime is 266720653. The reversal of 266720631 is 136027662.

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 266720631 - 2¹⁷ = 266589559 is a prime.

It is a super-2 number, since 2×266720631² = 142279790002076322, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 266720592 and 266720601.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (266720681) 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, 44453436 + ... + 44453441.

It is an arithmetic number, because the mean of its divisors is an integer number (88906878).

Almost surely, 2^266720631 is an apocalyptic number.

266720631 is a deficient number, since it is larger than the sum of its proper divisors (88906881).

266720631 is an equidigital number, since it uses as much as digits as its factorization.

266720631 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 88906880.

The product of its (nonzero) digits is 18144, while the sum is 33.

The square root of 266720631 is about 16331.5838484821. The cubic root of 266720631 is about 643.7030051344.

The spelling of 266720631 in words is "two hundred sixty-six million, seven hundred twenty thousand, six hundred thirty-one".