81125707157 has 32 divisors (see below), whose sum is σ = 97829233920. Its totient is φ = 66361630720.

The previous prime is 81125707129. The next prime is 81125707177. The reversal of 81125707157 is 75170752118.

It is not a de Polignac number, because 81125707157 - 2¹⁶ = 81125641621 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81125707127) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 12766493 + ... + 12772845.

It is an arithmetic number, because the mean of its divisors is an integer number (3057163560).

Almost surely, 2^81125707157 is an apocalyptic number.

It is an amenable number.

81125707157 is a deficient number, since it is larger than the sum of its proper divisors (16703526763).

81125707157 is a wasteful number, since it uses less digits than its factorization.

81125707157 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9373.

The product of its (nonzero) digits is 137200, while the sum is 44.

The spelling of 81125707157 in words is "eighty-one billion, one hundred twenty-five million, seven hundred seven thousand, one hundred fifty-seven".