626531661 has 24 divisors (see below), whose sum is σ = 1079245440. Its totient is φ = 342451296.

The previous prime is 626531639. The next prime is 626531687. The reversal of 626531661 is 166135626.

626531661 is a `hidden beast` number, since 62 + 6 + 531 + 6 + 61 = 666.

It is not a de Polignac number, because 626531661 - 2¹¹ = 626529613 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (626530661) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 214746 + ... + 217643.

It is an arithmetic number, because the mean of its divisors is an integer number (44968560).

Almost surely, 2^626531661 is an apocalyptic number.

It is an amenable number.

626531661 is a deficient number, since it is larger than the sum of its proper divisors (452713779).

626531661 is a wasteful number, since it uses less digits than its factorization.

626531661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 432425 (or 432422 counting only the distinct ones).

The product of its digits is 38880, while the sum is 36.

The square root of 626531661 is about 25030.6144750783. The cubic root of 626531661 is about 855.6858311698.

The spelling of 626531661 in words is "six hundred twenty-six million, five hundred thirty-one thousand, six hundred sixty-one".