398405897 has 8 divisors (see below), whose sum is σ = 432131112. Its totient is φ = 365824000.

The previous prime is 398405801. The next prime is 398405911. The reversal of 398405897 is 798504893.

It can be written as a sum of positive squares in 4 ways, for example, as 5216656 + 393189241 = 2284^2 + 19829^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 398405897 - 2⁸ = 398405641 is a prime.

It is a super-3 number, since 3×398405897³ (a number of 27 digits) contains 333 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (398405297) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 285104 + ... + 286497.

It is an arithmetic number, because the mean of its divisors is an integer number (54016389).

Almost surely, 2^398405897 is an apocalyptic number.

It is an amenable number.

398405897 is a deficient number, since it is larger than the sum of its proper divisors (33725215).

398405897 is a wasteful number, since it uses less digits than its factorization.

398405897 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 571659.

The product of its (nonzero) digits is 2177280, while the sum is 53.

The square root of 398405897 is about 19960.1076399903. The cubic root of 398405897 is about 735.8262089907.

The spelling of 398405897 in words is "three hundred ninety-eight million, four hundred five thousand, eight hundred ninety-seven".