2638513561 has 2 divisors, whose sum is σ = 2638513562. Its totient is φ = 2638513560.

The previous prime is 2638513523. The next prime is 2638513567. The reversal of 2638513561 is 1653158362.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 2547119961 + 91393600 = 50469^2 + 9560^2 .

It is a cyclic number.

It is not a de Polignac number, because 2638513561 - 2¹³ = 2638505369 is a prime.

It is not a weakly prime, because it can be changed into another prime (2638513567) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1319256780 + 1319256781.

It is an arithmetic number, because the mean of its divisors is an integer number (1319256781).

Almost surely, 2^2638513561 is an apocalyptic number.

It is an amenable number.

2638513561 is a deficient number, since it is larger than the sum of its proper divisors (1).

2638513561 is an equidigital number, since it uses as much as digits as its factorization.

2638513561 is an evil number, because the sum of its binary digits is even.

The product of its digits is 129600, while the sum is 40.

The square root of 2638513561 is about 51366.4633880901. The cubic root of 2638513561 is about 1381.8252053191.

The spelling of 2638513561 in words is "two billion, six hundred thirty-eight million, five hundred thirteen thousand, five hundred sixty-one".