661523053 has 2 divisors, whose sum is σ = 661523054. Its totient is φ = 661523052.

The previous prime is 661523047. The next prime is 661523077. The reversal of 661523053 is 350325166.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 653211364 + 8311689 = 25558^2 + 2883^2 .

It is a cyclic number.

It is not a de Polignac number, because 661523053 - 2²¹ = 659425901 is a prime.

It is a super-2 number, since 2×661523053² = 875225499300881618, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (661523453) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 330761526 + 330761527.

It is an arithmetic number, because the mean of its divisors is an integer number (330761527).

Almost surely, 2^661523053 is an apocalyptic number.

It is an amenable number.

661523053 is a deficient number, since it is larger than the sum of its proper divisors (1).

661523053 is an equidigital number, since it uses as much as digits as its factorization.

661523053 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 16200, while the sum is 31.

The square root of 661523053 is about 25720.0904547399. The cubic root of 661523053 is about 871.3279816054.

The spelling of 661523053 in words is "six hundred sixty-one million, five hundred twenty-three thousand, fifty-three".