631279261 has 8 divisors (see below), whose sum is σ = 635648760. Its totient is φ = 626921472.

The previous prime is 631279219. The next prime is 631279267. The reversal of 631279261 is 162972136.

It can be written as a sum of positive squares in 4 ways, for example, as 6579225 + 624700036 = 2565^2 + 24994^2 .

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-631279261 is a prime.

It is a super-2 number, since 2×631279261² = 797027010737412242, 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 631279261.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (631279267) 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, 123525 + ... + 128533.

It is an arithmetic number, because the mean of its divisors is an integer number (79456095).

Almost surely, 2^631279261 is an apocalyptic number.

It is an amenable number.

631279261 is a deficient number, since it is larger than the sum of its proper divisors (4369499).

631279261 is a wasteful number, since it uses less digits than its factorization.

631279261 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5855.

The product of its digits is 27216, while the sum is 37.

The square root of 631279261 is about 25125.2713617187. The cubic root of 631279261 is about 857.8417402169.

The spelling of 631279261 in words is "six hundred thirty-one million, two hundred seventy-nine thousand, two hundred sixty-one".