651100661 has 2 divisors, whose sum is σ = 651100662. Its totient is φ = 651100660.

The previous prime is 651100649. The next prime is 651100669. The reversal of 651100661 is 166001156.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 641051761 + 10048900 = 25319^2 + 3170^2 .

It is a cyclic number.

It is not a de Polignac number, because 651100661 - 2¹⁰ = 651099637 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 651100661.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (651100669) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 325550330 + 325550331.

It is an arithmetic number, because the mean of its divisors is an integer number (325550331).

Almost surely, 2^651100661 is an apocalyptic number.

It is an amenable number.

651100661 is a deficient number, since it is larger than the sum of its proper divisors (1).

651100661 is an equidigital number, since it uses as much as digits as its factorization.

651100661 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1080, while the sum is 26.

The square root of 651100661 is about 25516.6741759188. The cubic root of 651100661 is about 866.7277709547.

The spelling of 651100661 in words is "six hundred fifty-one million, one hundred thousand, six hundred sixty-one".