157761681 has 16 divisors (see below), whose sum is σ = 262253568. Its totient is φ = 81954000.

The previous prime is 157761679. The next prime is 157761689. The reversal of 157761681 is 186167751.

It is a happy number.

It is not a de Polignac number, because 157761681 - 2¹ = 157761679 is a prime.

It is a super-2 number, since 2×157761681² = 49777495983891522, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (157761689) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 341245 + ... + 341706.

It is an arithmetic number, because the mean of its divisors is an integer number (16390848).

Almost surely, 2^157761681 is an apocalyptic number.

157761681 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

157761681 is a deficient number, since it is larger than the sum of its proper divisors (104491887).

157761681 is a wasteful number, since it uses less digits than its factorization.

157761681 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 682972.

The product of its digits is 70560, while the sum is 42.

The square root of 157761681 is about 12560.3216917402. The cubic root of 157761681 is about 540.3400704288.

The spelling of 157761681 in words is "one hundred fifty-seven million, seven hundred sixty-one thousand, six hundred eighty-one".