651806993 has 2 divisors, whose sum is σ = 651806994. Its totient is φ = 651806992.

The previous prime is 651806983. The next prime is 651807007. The reversal of 651806993 is 399608156.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 562069264 + 89737729 = 23708^2 + 9473^2 .

It is a cyclic number.

It is not a de Polignac number, because 651806993 - 2⁴ = 651806977 is a prime.

It is a super-2 number, since 2×651806993² = 849704712247404098, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (651806963) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 325903496 + 325903497.

It is an arithmetic number, because the mean of its divisors is an integer number (325903497).

Almost surely, 2^651806993 is an apocalyptic number.

It is an amenable number.

651806993 is a deficient number, since it is larger than the sum of its proper divisors (1).

651806993 is an equidigital number, since it uses as much as digits as its factorization.

651806993 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 349920, while the sum is 47.

The square root of 651806993 is about 25530.5110211292. The cubic root of 651806993 is about 867.0410744389.

The spelling of 651806993 in words is "six hundred fifty-one million, eight hundred six thousand, nine hundred ninety-three".