215152391 has 4 divisors (see below), whose sum is σ = 227808432. Its totient is φ = 202496352.

The previous prime is 215152381. The next prime is 215152397. The reversal of 215152391 is 193251512.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 215152391 - 2²² = 210958087 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (215152397) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6327995 + ... + 6328028.

It is an arithmetic number, because the mean of its divisors is an integer number (56952108).

Almost surely, 2^215152391 is an apocalyptic number.

215152391 is a deficient number, since it is larger than the sum of its proper divisors (12656041).

215152391 is a wasteful number, since it uses less digits than its factorization.

215152391 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12656040.

The product of its digits is 2700, while the sum is 29.

The square root of 215152391 is about 14668.0738680987. The cubic root of 215152391 is about 599.2141480290.

The spelling of 215152391 in words is "two hundred fifteen million, one hundred fifty-two thousand, three hundred ninety-one".