1921673880 has 384 divisors, whose sum is σ = 7806689280. Its totient is φ = 399790080.

The previous prime is 1921673879. The next prime is 1921673891. The reversal of 1921673880 is 883761291.

It is a hoax number, since the sum of its digits (45) coincides with the sum of the digits of its distinct prime factors.

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 1327317 + ... + 1328763.

It is an arithmetic number, because the mean of its divisors is an integer number (20329920).

Almost surely, 2^1921673880 is an apocalyptic number.

1921673880 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 1921673880, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3903344640).

1921673880 is an abundant number, since it is smaller than the sum of its proper divisors (5885015400).

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

1921673880 is a wasteful number, since it uses less digits than its factorization.

1921673880 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1519 (or 1512 counting only the distinct ones).

The product of its (nonzero) digits is 145152, while the sum is 45.

The square root of 1921673880 is about 43836.9008941097. The cubic root of 1921673880 is about 1243.2540873543.

It can be divided in two parts, 19216 and 73880, that added together give a triangular number (93096 = T₄₃₁).

The spelling of 1921673880 in words is "one billion, nine hundred twenty-one million, six hundred seventy-three thousand, eight hundred eighty".