1601661651 has 8 divisors (see below), whose sum is σ = 2138134464. Its totient is φ = 1066481640.

The previous prime is 1601661631. The next prime is 1601661653. The reversal of 1601661651 is 1561661061.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 1601661651 - 2²⁹ = 1064790739 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1601661653) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 320305 + ... + 325266.

It is an arithmetic number, because the mean of its divisors is an integer number (267266808).

Almost surely, 2^1601661651 is an apocalyptic number.

1601661651 is a deficient number, since it is larger than the sum of its proper divisors (536472813).

1601661651 is an equidigital number, since it uses as much as digits as its factorization.

1601661651 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 646401.

The product of its (nonzero) digits is 6480, while the sum is 33.

The square root of 1601661651 is about 40020.7652475562. The cubic root of 1601661651 is about 1170.0118466183.

The spelling of 1601661651 in words is "one billion, six hundred one million, six hundred sixty-one thousand, six hundred fifty-one".