10115905661 has 4 divisors (see below), whose sum is σ = 10125814524. Its totient is φ = 10105996800.

The previous prime is 10115905651. The next prime is 10115905693. The reversal of 10115905661 is 16650951101.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 16650951101 = 257 ⋅64789693.

It can be written as a sum of positive squares in 2 ways, for example, as 3340146436 + 6775759225 = 57794^2 + 82315^2 .

It is a cyclic number.

It is not a de Polignac number, because 10115905661 - 2¹⁰ = 10115904637 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (10115905601) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4952900 + ... + 4954941.

It is an arithmetic number, because the mean of its divisors is an integer number (2531453631).

Almost surely, 2^10115905661 is an apocalyptic number.

It is an amenable number.

10115905661 is a deficient number, since it is larger than the sum of its proper divisors (9908863).

10115905661 is an equidigital number, since it uses as much as digits as its factorization.

10115905661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9908862.

The product of its (nonzero) digits is 8100, while the sum is 35.

The spelling of 10115905661 in words is "ten billion, one hundred fifteen million, nine hundred five thousand, six hundred sixty-one".