661634627 has 2 divisors, whose sum is σ = 661634628. Its totient is φ = 661634626.

The previous prime is 661634569. The next prime is 661634639. The reversal of 661634627 is 726436166.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 661634627 - 2⁸ = 661634371 is a prime.

It is not a weakly prime, because it can be changed into another prime (661634647) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 330817313 + 330817314.

It is an arithmetic number, because the mean of its divisors is an integer number (330817314).

Almost surely, 2^661634627 is an apocalyptic number.

661634627 is a deficient number, since it is larger than the sum of its proper divisors (1).

661634627 is an equidigital number, since it uses as much as digits as its factorization.

661634627 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 217728, while the sum is 41.

The square root of 661634627 is about 25722.2593681037. The cubic root of 661634627 is about 871.3769655789.

The spelling of 661634627 in words is "six hundred sixty-one million, six hundred thirty-four thousand, six hundred twenty-seven".