11215780731 has 24 divisors (see below), whose sum is σ = 17098328000. Its totient is φ = 7064919792.

The previous prime is 11215780729. The next prime is 11215780777. The reversal of 11215780731 is 13708751211.

11215780731 is a `hidden beast` number, since 1 + 12 + 1 + 578 + 0 + 73 + 1 = 666.

It is not a de Polignac number, because 11215780731 - 2¹ = 11215780729 is a prime.

It is a super-2 number, since 2×11215780731² (a number of 21 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (11215780721) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 21721 + ... + 151338.

Almost surely, 2^11215780731 is an apocalyptic number.

11215780731 is a deficient number, since it is larger than the sum of its proper divisors (5882547269).

11215780731 is a wasteful number, since it uses less digits than its factorization.

11215780731 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 173463 (or 173460 counting only the distinct ones).

The product of its (nonzero) digits is 11760, while the sum is 36.

The spelling of 11215780731 in words is "eleven billion, two hundred fifteen million, seven hundred eighty thousand, seven hundred thirty-one".