1517601661 has 4 divisors (see below), whose sum is σ = 1525228000. Its totient is φ = 1509975324.

The previous prime is 1517601647. The next prime is 1517601667. The reversal of 1517601661 is 1661067151.

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 a cyclic number.

It is not a de Polignac number, because 1517601661 - 2¹⁷ = 1517470589 is a prime.

It is a super-2 number, since 2×1517601661² = 4606229602939917842, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1517601667) 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, 3812871 + ... + 3813268.

It is an arithmetic number, because the mean of its divisors is an integer number (381307000).

Almost surely, 2^1517601661 is an apocalyptic number.

It is an amenable number.

1517601661 is a deficient number, since it is larger than the sum of its proper divisors (7626339).

1517601661 is an equidigital number, since it uses as much as digits as its factorization.

1517601661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7626338.

The product of its (nonzero) digits is 7560, while the sum is 34.

The square root of 1517601661 is about 38956.4071880352. The cubic root of 1517601661 is about 1149.1743692034.

The spelling of 1517601661 in words is "one billion, five hundred seventeen million, six hundred one thousand, six hundred sixty-one".