1661164784 has 20 divisors (see below), whose sum is σ = 3222569784. Its totient is φ = 829533888.

The previous prime is 1661164783. The next prime is 1661164789. The reversal of 1661164784 is 4874611661.

It is a super-4 number, since 4×1661164784⁴ (a number of 38 digits) contains 4444 as substring.

It is a hoax number, since the sum of its digits (44) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1661164783) 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, 52382 + ... + 77885.

Almost surely, 2^1661164784 is an apocalyptic number.

It is an amenable number.

1661164784 is a deficient number, since it is larger than the sum of its proper divisors (1561405000).

1661164784 is a wasteful number, since it uses less digits than its factorization.

1661164784 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 131072 (or 131066 counting only the distinct ones).

The product of its digits is 193536, while the sum is 44.

The square root of 1661164784 is about 40757.3893177667. The cubic root of 1661164784 is about 1184.3250226208.

The spelling of 1661164784 in words is "one billion, six hundred sixty-one million, one hundred sixty-four thousand, seven hundred eighty-four".