661083660451 has 2 divisors, whose sum is σ = 661083660452. Its totient is φ = 661083660450.

The previous prime is 661083660437. The next prime is 661083660529. The reversal of 661083660451 is 154066380166.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 661083660451 - 2¹³ = 661083652259 is a prime.

It is a super-2 number, since 2×661083660451² (a number of 24 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (661083660551) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 330541830225 + 330541830226.

It is an arithmetic number, because the mean of its divisors is an integer number (330541830226).

Almost surely, 2^661083660451 is an apocalyptic number.

661083660451 is a deficient number, since it is larger than the sum of its proper divisors (1).

661083660451 is an equidigital number, since it uses as much as digits as its factorization.

661083660451 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 622080, while the sum is 46.

The spelling of 661083660451 in words is "six hundred sixty-one billion, eighty-three million, six hundred sixty thousand, four hundred fifty-one".