661650793 has 2 divisors, whose sum is σ = 661650794. Its totient is φ = 661650792.

The previous prime is 661650751. The next prime is 661650811. The reversal of 661650793 is 397056166.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 417916249 + 243734544 = 20443^2 + 15612^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-661650793 is a prime.

It is not a weakly prime, because it can be changed into another prime (661650193) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 330825396 + 330825397.

It is an arithmetic number, because the mean of its divisors is an integer number (330825397).

Almost surely, 2^661650793 is an apocalyptic number.

It is an amenable number.

661650793 is a deficient number, since it is larger than the sum of its proper divisors (1).

661650793 is an equidigital number, since it uses as much as digits as its factorization.

661650793 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 204120, while the sum is 43.

The square root of 661650793 is about 25722.5736076311. The cubic root of 661650793 is about 871.3840624290.

The spelling of 661650793 in words is "six hundred sixty-one million, six hundred fifty thousand, seven hundred ninety-three".