637626961 has 4 divisors (see below), whose sum is σ = 648079924. Its totient is φ = 627174000.

The previous prime is 637626943. The next prime is 637626967. The reversal of 637626961 is 169626736.

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

It can be written as a sum of positive squares in 2 ways, for example, as 78588225 + 559038736 = 8865^2 + 23644^2 .

It is a cyclic number.

It is not a de Polignac number, because 637626961 - 2¹¹ = 637624913 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (637626967) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5226390 + ... + 5226511.

It is an arithmetic number, because the mean of its divisors is an integer number (162019981).

Almost surely, 2^637626961 is an apocalyptic number.

637626961 is a gapful number since it is divisible by the number (61) formed by its first and last digit.

It is an amenable number.

637626961 is a deficient number, since it is larger than the sum of its proper divisors (10452963).

637626961 is a wasteful number, since it uses less digits than its factorization.

637626961 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10452962.

The product of its digits is 489888, while the sum is 46.

The square root of 637626961 is about 25251.2764231830. The cubic root of 637626961 is about 860.7074407010.

The spelling of 637626961 in words is "six hundred thirty-seven million, six hundred twenty-six thousand, nine hundred sixty-one".