2637601661 has 2 divisors, whose sum is σ = 2637601662. Its totient is φ = 2637601660.

The previous prime is 2637601651. The next prime is 2637601691. The reversal of 2637601661 is 1661067362.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1383096100 + 1254505561 = 37190^2 + 35419^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-2637601661 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2637601621) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1318800830 + 1318800831.

It is an arithmetic number, because the mean of its divisors is an integer number (1318800831).

Almost surely, 2^2637601661 is an apocalyptic number.

It is an amenable number.

2637601661 is a deficient number, since it is larger than the sum of its proper divisors (1).

2637601661 is an equidigital number, since it uses as much as digits as its factorization.

2637601661 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 54432, while the sum is 38.

The square root of 2637601661 is about 51357.5862069081. The cubic root of 2637601661 is about 1381.6659955254.

The spelling of 2637601661 in words is "two billion, six hundred thirty-seven million, six hundred one thousand, six hundred sixty-one".