1661874690 has 48 divisors (see below), whose sum is σ = 4639686912. Its totient is φ = 379856736.

The previous prime is 1661874659. The next prime is 1661874701. The reversal of 1661874690 is 964781661.

It is a happy number.

It is a super-2 number, since 2×1661874690² = 5523654970525192200, which contains 22 as substring.

It is a Curzon number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 563794 + ... + 566733.

It is an arithmetic number, because the mean of its divisors is an integer number (96660144).

Almost surely, 2^1661874690 is an apocalyptic number.

1661874690 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

1661874690 is an abundant number, since it is smaller than the sum of its proper divisors (2977812222).

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

1661874690 is a wasteful number, since it uses less digits than its factorization.

1661874690 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1130551 (or 1130544 counting only the distinct ones).

The product of its (nonzero) digits is 435456, while the sum is 48.

The square root of 1661874690 is about 40766.0973113689. The cubic root of 1661874690 is about 1184.4937074113.

The spelling of 1661874690 in words is "one billion, six hundred sixty-one million, eight hundred seventy-four thousand, six hundred ninety".