1921669690 has 16 divisors (see below), whose sum is σ = 3641058720. Its totient is φ = 728211600.

The previous prime is 1921669667. The next prime is 1921669693. The reversal of 1921669690 is 969661291.

It is a super-2 number, since 2×1921669690² = 7385628794929392200, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (1921669693) 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, 5056836 + ... + 5057215.

It is an arithmetic number, because the mean of its divisors is an integer number (227566170).

Almost surely, 2^1921669690 is an apocalyptic number.

1921669690 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

1921669690 is a deficient number, since it is larger than the sum of its proper divisors (1719389030).

1921669690 is a wasteful number, since it uses less digits than its factorization.

1921669690 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10114077.

The product of its (nonzero) digits is 314928, while the sum is 49.

The square root of 1921669690 is about 43836.8531032965. The cubic root of 1921669690 is about 1243.2531837604.

The spelling of 1921669690 in words is "one billion, nine hundred twenty-one million, six hundred sixty-nine thousand, six hundred ninety".