1641679920 has 320 divisors, whose sum is σ = 5868195840. Its totient is φ = 421604352.

The previous prime is 1641679913. The next prime is 1641679943. The reversal of 1641679920 is 299761461.

It is a super-2 number, since 2×1641679920² = 5390225919462412800, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 10456482 + ... + 10456638.

It is an arithmetic number, because the mean of its divisors is an integer number (18338112).

Almost surely, 2^1641679920 is an apocalyptic number.

1641679920 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1641679920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2934097920).

1641679920 is an abundant number, since it is smaller than the sum of its proper divisors (4226515920).

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

1641679920 is a wasteful number, since it uses less digits than its factorization.

1641679920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 329 (or 317 counting only the distinct ones).

The product of its (nonzero) digits is 163296, while the sum is 45.

The square root of 1641679920 is about 40517.6494875998. The cubic root of 1641679920 is about 1179.6762302372.

It can be divided in two parts, 16 and 41679920, that added together give a square (41679936 = 6456²).

The spelling of 1641679920 in words is "one billion, six hundred forty-one million, six hundred seventy-nine thousand, nine hundred twenty".