390197421 has 6 divisors (see below), whose sum is σ = 563618510. Its totient is φ = 260131608.

The previous prime is 390197393. The next prime is 390197429. The reversal of 390197421 is 124791093.

It can be written as a sum of positive squares in only one way, i.e., 256448196 + 133749225 = 16014^2 + 11565^2 .

It is not a de Polignac number, because 390197421 - 2⁵ = 390197389 is a prime.

It is a super-3 number, since 3×390197421³ (a number of 27 digits) contains 333 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (390197429) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 21677626 + ... + 21677643.

Almost surely, 2^390197421 is an apocalyptic number.

It is an amenable number.

390197421 is a deficient number, since it is larger than the sum of its proper divisors (173421089).

390197421 is a wasteful number, since it uses less digits than its factorization.

390197421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 43355275 (or 43355272 counting only the distinct ones).

The product of its (nonzero) digits is 13608, while the sum is 36.

The square root of 390197421 is about 19753.4154261991. The cubic root of 390197421 is about 730.7376174795.

The spelling of 390197421 in words is "three hundred ninety million, one hundred ninety-seven thousand, four hundred twenty-one".