157761478636991 has 4 divisors (see below), whose sum is σ = 157761614973072. Its totient is φ = 157761342300912.

The previous prime is 157761478636873. The next prime is 157761478637057. The reversal of 157761478636991 is 199636874167751.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-157761478636991 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (157761478686991) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (31) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 66417326 + ... + 68751611.

It is an arithmetic number, because the mean of its divisors is an integer number (39440403743268).

Almost surely, 2^{157761478636991} is an apocalyptic number.

157761478636991 is a deficient number, since it is larger than the sum of its proper divisors (136336081).

157761478636991 is a wasteful number, since it uses less digits than its factorization.

157761478636991 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 136336080.

The product of its digits is 2880541440, while the sum is 80.

The spelling of 157761478636991 in words is "one hundred fifty-seven trillion, seven hundred sixty-one billion, four hundred seventy-eight million, six hundred thirty-six thousand, nine hundred ninety-one".