201515315531 has 4 divisors (see below), whose sum is σ = 201517252200. Its totient is φ = 201513378864.

The previous prime is 201515315527. The next prime is 201515315587. The reversal of 201515315531 is 135513515102.

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 201515315531 - 2² = 201515315527 is a prime.

It is a super-2 number, since 2×201515315531² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (201515315431) 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, 802826 + ... + 1023503.

It is an arithmetic number, because the mean of its divisors is an integer number (50379313050).

Almost surely, 2^201515315531 is an apocalyptic number.

201515315531 is a deficient number, since it is larger than the sum of its proper divisors (1936669).

201515315531 is a wasteful number, since it uses less digits than its factorization.

201515315531 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1936668.

The product of its (nonzero) digits is 11250, while the sum is 32.

The spelling of 201515315531 in words is "two hundred one billion, five hundred fifteen million, three hundred fifteen thousand, five hundred thirty-one".