651660551 has 2 divisors, whose sum is σ = 651660552. Its totient is φ = 651660550.

The previous prime is 651660547. The next prime is 651660563. The reversal of 651660551 is 155066156.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 651660551 - 2² = 651660547 is a prime.

It is a super-2 number, since 2×651660551² = 849322947459247202, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (651660511) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 325830275 + 325830276.

It is an arithmetic number, because the mean of its divisors is an integer number (325830276).

Almost surely, 2^651660551 is an apocalyptic number.

651660551 is a deficient number, since it is larger than the sum of its proper divisors (1).

651660551 is an equidigital number, since it uses as much as digits as its factorization.

651660551 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 27000, while the sum is 35.

The square root of 651660551 is about 25527.6428798274. The cubic root of 651660551 is about 866.9761366376.

The spelling of 651660551 in words is "six hundred fifty-one million, six hundred sixty thousand, five hundred fifty-one".