1601015661 has 36 divisors (see below), whose sum is σ = 2747414592. Its totient is φ = 895389264.

The previous prime is 1601015629. The next prime is 1601015687. The reversal of 1601015661 is 1665101061.

1601015661 is a `hidden beast` number, since 1 + 601 + 0 + 1 + 56 + 6 + 1 = 666.

It is not a de Polignac number, because 1601015661 - 2⁵ = 1601015629 is a prime.

It is a super-2 number, since 2×1601015661² = 5126502293534533842, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1601015161) by changing a digit.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 17895 + ... + 59348.

It is an arithmetic number, because the mean of its divisors is an integer number (76317072).

Almost surely, 2^1601015661 is an apocalyptic number.

It is an amenable number.

1601015661 is a deficient number, since it is larger than the sum of its proper divisors (1146398931).

1601015661 is a wasteful number, since it uses less digits than its factorization.

1601015661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 77310 (or 77300 counting only the distinct ones).

The product of its (nonzero) digits is 1080, while the sum is 27.

The square root of 1601015661 is about 40012.6937483594. The cubic root of 1601015661 is about 1169.8545271686.

The spelling of 1601015661 in words is "one billion, six hundred one million, fifteen thousand, six hundred sixty-one".