399703680 has 128 divisors (see below), whose sum is σ = 1415678400. Its totient is φ = 106583040.

The previous prime is 399703657. The next prime is 399703691. The reversal of 399703680 is 86307993.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (128).

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 15 ways as a sum of consecutive naturals, for example, 5715 + ... + 28845.

Almost surely, 2^399703680 is an apocalyptic number.

399703680 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 399703680, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (707839200).

399703680 is an abundant number, since it is smaller than the sum of its proper divisors (1015974720).

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

399703680 is a wasteful number, since it uses less digits than its factorization.

399703680 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 23159 (or 23141 counting only the distinct ones).

The product of its (nonzero) digits is 244944, while the sum is 45.

The square root of 399703680 is about 19992.5906275300. The cubic root of 399703680 is about 736.6243127464.

The spelling of 399703680 in words is "three hundred ninety-nine million, seven hundred three thousand, six hundred eighty".