1661693936 has 40 divisors (see below), whose sum is σ = 3741843840. Its totient is φ = 700081344.

The previous prime is 1661693933. The next prime is 1661693981. The reversal of 1661693936 is 6393961661.

It is a happy number.

It is a super-2 number, since 2×1661693936² = 5522453473878344192, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1661693933) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 119126 + ... + 132341.

It is an arithmetic number, because the mean of its divisors is an integer number (93546096).

Almost surely, 2^1661693936 is an apocalyptic number.

1661693936 is a gapful number since it is divisible by the number (16) formed by its first and last digit.

It is an amenable number.

1661693936 is an abundant number, since it is smaller than the sum of its proper divisors (2080149904).

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

1661693936 is a wasteful number, since it uses less digits than its factorization.

1661693936 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 251541 (or 251535 counting only the distinct ones).

The product of its digits is 944784, while the sum is 50.

The square root of 1661693936 is about 40763.8802863515. The cubic root of 1661693936 is about 1184.4507619875.

The spelling of 1661693936 in words is "one billion, six hundred sixty-one million, six hundred ninety-three thousand, nine hundred thirty-six".