111691615949 has 2 divisors, whose sum is σ = 111691615950. Its totient is φ = 111691615948.

The previous prime is 111691615939. The next prime is 111691615979. The reversal of 111691615949 is 949516196111.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 109324793449 + 2366822500 = 330643^2 + 48650^2 .

It is a cyclic number.

It is not a de Polignac number, because 111691615949 - 2⁴ = 111691615933 is a prime.

It is a super-2 number, since 2×111691615949² (a number of 23 digits) contains 22 as substring.

It is a Sophie Germain prime.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 111691615949.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (111691615939) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 55845807974 + 55845807975.

It is an arithmetic number, because the mean of its divisors is an integer number (55845807975).

Almost surely, 2^111691615949 is an apocalyptic number.

It is an amenable number.

111691615949 is a deficient number, since it is larger than the sum of its proper divisors (1).

111691615949 is an equidigital number, since it uses as much as digits as its factorization.

111691615949 is an evil number, because the sum of its binary digits is even.

The product of its digits is 524880, while the sum is 53.

The spelling of 111691615949 in words is "one hundred eleven billion, six hundred ninety-one million, six hundred fifteen thousand, nine hundred forty-nine".