615470991 has 4 divisors (see below), whose sum is σ = 820627992. Its totient is φ = 410313992.

The previous prime is 615470953. The next prime is 615471001. The reversal of 615470991 is 199074516.

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 615470991 - 2¹⁵ = 615438223 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (615470491) 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, 102578496 + ... + 102578501.

It is an arithmetic number, because the mean of its divisors is an integer number (205156998).

Almost surely, 2^615470991 is an apocalyptic number.

615470991 is a deficient number, since it is larger than the sum of its proper divisors (205157001).

615470991 is a wasteful number, since it uses less digits than its factorization.

615470991 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 205157000.

The product of its (nonzero) digits is 68040, while the sum is 42.

The square root of 615470991 is about 24808.6878129417. The cubic root of 615470991 is about 850.6205346481.

The spelling of 615470991 in words is "six hundred fifteen million, four hundred seventy thousand, nine hundred ninety-one".