399981120 has 336 divisors, whose sum is σ = 1613659968. Its totient is φ = 83005440.

The previous prime is 399981107. The next prime is 399981157. The reversal of 399981120 is 21189993.

It is a tau number, because it is divible by the number of its divisors (336).

It is a Harshad number since it is a multiple of its sum of digits (42).

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 517054 + ... + 517826.

Almost surely, 2^399981120 is an apocalyptic number.

399981120 is a gapful number since it is divisible by the number (30) 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 399981120, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (806829984).

399981120 is an abundant number, since it is smaller than the sum of its proper divisors (1213678848).

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

399981120 is a wasteful number, since it uses less digits than its factorization.

399981120 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 818 (or 801 counting only the distinct ones).

The product of its (nonzero) digits is 34992, while the sum is 42.

The square root of 399981120 is about 19999.5279944303. The cubic root of 399981120 is about 736.7947071266.

The spelling of 399981120 in words is "three hundred ninety-nine million, nine hundred eighty-one thousand, one hundred twenty".