215491397 has 8 divisors (see below), whose sum is σ = 235280160. Its totient is φ = 195735760.

The previous prime is 215491351. The next prime is 215491411. The reversal of 215491397 is 793194512.

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

It is a de Polignac number, because none of the positive numbers 2^k-215491397 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (215491307) 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, 6479 + ... + 21747.

It is an arithmetic number, because the mean of its divisors is an integer number (29410020).

Almost surely, 2^215491397 is an apocalyptic number.

It is an amenable number.

215491397 is a deficient number, since it is larger than the sum of its proper divisors (19788763).

215491397 is a wasteful number, since it uses less digits than its factorization.

215491397 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16563.

The product of its digits is 68040, while the sum is 41.

The square root of 215491397 is about 14679.6252336359. The cubic root of 215491397 is about 599.5287011889.

The spelling of 215491397 in words is "two hundred fifteen million, four hundred ninety-one thousand, three hundred ninety-seven".