1920401840 has 80 divisors (see below), whose sum is σ = 5125600512. Its totient is φ = 655479552.

The previous prime is 1920401827. The next prime is 1920401849. The reversal of 1920401840 is 481040291.

It is a tau number, because it is divible by the number of its divisors (80).

It is not an unprimeable number, because it can be changed into a prime (1920401849) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 119567 + ... + 134673.

Almost surely, 2^1920401840 is an apocalyptic number.

1920401840 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 1920401840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2562800256).

1920401840 is an abundant number, since it is smaller than the sum of its proper divisors (3205198672).

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

1920401840 is a wasteful number, since it uses less digits than its factorization.

1920401840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15354 (or 15348 counting only the distinct ones).

The product of its (nonzero) digits is 2304, while the sum is 29.

The square root of 1920401840 is about 43822.3897111967. The cubic root of 1920401840 is about 1242.9797053824.

The spelling of 1920401840 in words is "one billion, nine hundred twenty million, four hundred one thousand, eight hundred forty".