399135690 has 48 divisors (see below), whose sum is σ = 1098801288. Its totient is φ = 100174848.

The previous prime is 399135661. The next prime is 399135691. The reversal of 399135690 is 96531993.

It can be written as a sum of positive squares in 4 ways, for example, as 398840841 + 294849 = 19971^2 + 543^2 .

It is a super-2 number, since 2×399135690² = 318618598063552200, which contains 22 as substring.

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

It is not an unprimeable number, because it can be changed into a prime (399135691) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 128907 + ... + 131966.

Almost surely, 2^399135690 is an apocalyptic number.

399135690 is a gapful number since it is divisible by the number (30) formed by its first and last digit.

399135690 is an abundant number, since it is smaller than the sum of its proper divisors (699665598).

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

399135690 is a wasteful number, since it uses less digits than its factorization.

399135690 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 260903 (or 260900 counting only the distinct ones).

The product of its (nonzero) digits is 196830, while the sum is 45.

The square root of 399135690 is about 19978.3805650008. The cubic root of 399135690 is about 736.2752261566.

The spelling of 399135690 in words is "three hundred ninety-nine million, one hundred thirty-five thousand, six hundred ninety".