2661506401 has 2 divisors, whose sum is σ = 2661506402. Its totient is φ = 2661506400.

The previous prime is 2661506381. The next prime is 2661506413. The reversal of 2661506401 is 1046051662.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 2626460001 + 35046400 = 51249^2 + 5920^2 .

It is a cyclic number.

It is not a de Polignac number, because 2661506401 - 2⁵ = 2661506369 is a prime.

It is not a weakly prime, because it can be changed into another prime (2661506201) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1330753200 + 1330753201.

It is an arithmetic number, because the mean of its divisors is an integer number (1330753201).

Almost surely, 2^2661506401 is an apocalyptic number.

It is an amenable number.

2661506401 is a deficient number, since it is larger than the sum of its proper divisors (1).

2661506401 is an equidigital number, since it uses as much as digits as its factorization.

2661506401 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 8640, while the sum is 31.

The square root of 2661506401 is about 51589.7896971872. The cubic root of 2661506401 is about 1385.8274890149.

The spelling of 2661506401 in words is "two billion, six hundred sixty-one million, five hundred six thousand, four hundred one".