1915237661 has 2 divisors, whose sum is σ = 1915237662. Its totient is φ = 1915237660.

The previous prime is 1915237657. The next prime is 1915237703. The reversal of 1915237661 is 1667325191.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1553857561 + 361380100 = 39419^2 + 19010^2 .

It is a cyclic number.

It is not a de Polignac number, because 1915237661 - 2² = 1915237657 is a prime.

It is a super-2 number, since 2×1915237661² = 7336270596225501842, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1915237651) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 957618830 + 957618831.

It is an arithmetic number, because the mean of its divisors is an integer number (957618831).

Almost surely, 2^1915237661 is an apocalyptic number.

It is an amenable number.

1915237661 is a deficient number, since it is larger than the sum of its proper divisors (1).

1915237661 is an equidigital number, since it uses as much as digits as its factorization.

1915237661 is an evil number, because the sum of its binary digits is even.

The product of its digits is 68040, while the sum is 41.

The square root of 1915237661 is about 43763.4283506217. The cubic root of 1915237661 is about 1241.8645339030.

The spelling of 1915237661 in words is "one billion, nine hundred fifteen million, two hundred thirty-seven thousand, six hundred sixty-one".