15611601 has 4 divisors (see below), whose sum is σ = 20815472. Its totient is φ = 10407732.

The previous prime is 15611591. The next prime is 15611633. The reversal of 15611601 is 10611651.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 15611601 - 2¹⁷ = 15480529 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (15611681) 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, 2601931 + ... + 2601936.

It is an arithmetic number, because the mean of its divisors is an integer number (5203868).

Almost surely, 2^15611601 is an apocalyptic number.

It is an amenable number.

15611601 is a deficient number, since it is larger than the sum of its proper divisors (5203871).

15611601 is an equidigital number, since it uses as much as digits as its factorization.

15611601 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5203870.

The product of its (nonzero) digits is 180, while the sum is 21.

The square root of 15611601 is about 3951.1518573702. The cubic root of 15611601 is about 249.9285182300.

The spelling of 15611601 in words is "fifteen million, six hundred eleven thousand, six hundred one".