397221515 has 16 divisors (see below), whose sum is σ = 480111840. Its totient is φ = 315490560.

The previous prime is 397221479. The next prime is 397221521. The reversal of 397221515 is 515122793.

It is not a de Polignac number, because 397221515 - 2¹² = 397217419 is a prime.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 643487 + ... + 644103.

It is an arithmetic number, because the mean of its divisors is an integer number (30006990).

Almost surely, 2^397221515 is an apocalyptic number.

397221515 is a deficient number, since it is larger than the sum of its proper divisors (82890325).

397221515 is a wasteful number, since it uses less digits than its factorization.

397221515 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1342.

The product of its digits is 18900, while the sum is 35.

The square root of 397221515 is about 19930.4168295598. The cubic root of 397221515 is about 735.0963299476.

The spelling of 397221515 in words is "three hundred ninety-seven million, two hundred twenty-one thousand, five hundred fifteen".