1601665815 has 16 divisors (see below), whose sum is σ = 2579868000. Its totient is φ = 848487552.

The previous prime is 1601665811. The next prime is 1601665817. The reversal of 1601665815 is 5185661061.

It is not a de Polignac number, because 1601665815 - 2² = 1601665811 is a prime.

It is a super-2 number, since 2×1601665815² = 5130666765879228450, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1601665811) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 356080 + ... + 360549.

It is an arithmetic number, because the mean of its divisors is an integer number (161241750).

Almost surely, 2^1601665815 is an apocalyptic number.

1601665815 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

1601665815 is a deficient number, since it is larger than the sum of its proper divisors (978202185).

1601665815 is a wasteful number, since it uses less digits than its factorization.

1601665815 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 716786.

The product of its (nonzero) digits is 43200, while the sum is 39.

The square root of 1601665815 is about 40020.8172705156. The cubic root of 1601665815 is about 1170.0128605497.

The spelling of 1601665815 in words is "one billion, six hundred one million, six hundred sixty-five thousand, eight hundred fifteen".