661567037 has 2 divisors, whose sum is σ = 661567038. Its totient is φ = 661567036.

The previous prime is 661566973. The next prime is 661567073. The reversal of 661567037 is 730765166.

Together with next prime (661567073) it forms an Ormiston pair, because they use the same digits, order apart.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 386869561 + 274697476 = 19669^2 + 16574^2 .

It is a cyclic number.

It is not a de Polignac number, because 661567037 - 2⁶ = 661566973 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 661566985 and 661567003.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (661567237) 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, 330783518 + 330783519.

It is an arithmetic number, because the mean of its divisors is an integer number (330783519).

Almost surely, 2^661567037 is an apocalyptic number.

It is an amenable number.

661567037 is a deficient number, since it is larger than the sum of its proper divisors (1).

661567037 is an equidigital number, since it uses as much as digits as its factorization.

661567037 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 158760, while the sum is 41.

The square root of 661567037 is about 25720.9454919527. The cubic root of 661567037 is about 871.3472924167.

The spelling of 661567037 in words is "six hundred sixty-one million, five hundred sixty-seven thousand, thirty-seven".