1661644746 has 32 divisors (see below), whose sum is σ = 3698032320. Its totient is φ = 553058352.

The previous prime is 1661644739. The next prime is 1661644757. The reversal of 1661644746 is 6474461661.

1661644746 is a `hidden beast` number, since 16 + 6 + 164 + 474 + 6 = 666.

It is a super-2 number, since 2×1661644746² = 5522126523818809032, which contains 22 as substring.

It is a Smith number, since the sum of its digits (45) coincides with the sum of the digits of its prime factors.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 14356 + ... + 59408.

It is an arithmetic number, because the mean of its divisors is an integer number (115563510).

Almost surely, 2^1661644746 is an apocalyptic number.

1661644746 is an abundant number, since it is smaller than the sum of its proper divisors (2036387574).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1661644746 is a wasteful number, since it uses less digits than its factorization.

1661644746 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 45747 (or 45741 counting only the distinct ones).

The product of its digits is 580608, while the sum is 45.

The square root of 1661644746 is about 40763.2769291184. The cubic root of 1661644746 is about 1184.4390743744.

The spelling of 1661644746 in words is "one billion, six hundred sixty-one million, six hundred forty-four thousand, seven hundred forty-six".