626238661 has 6 divisors (see below), whose sum is σ = 632388390. Its totient is φ = 620148168.

The previous prime is 626238649. The next prime is 626238667. The reversal of 626238661 is 166832626.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 432889636 + 193349025 = 20806^2 + 13905^2 .

It is not a de Polignac number, because 626238661 - 2⁵ = 626238629 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (626238667) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 18906 + ... + 40123.

It is an arithmetic number, because the mean of its divisors is an integer number (105398065).

Almost surely, 2^626238661 is an apocalyptic number.

It is an amenable number.

626238661 is a deficient number, since it is larger than the sum of its proper divisors (6149729).

626238661 is an equidigital number, since it uses as much as digits as its factorization.

626238661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 59235 (or 59132 counting only the distinct ones).

The product of its digits is 124416, while the sum is 40.

The square root of 626238661 is about 25024.7609578993. The cubic root of 626238661 is about 855.5524220877.

The spelling of 626238661 in words is "six hundred twenty-six million, two hundred thirty-eight thousand, six hundred sixty-one".