155231681 has 4 divisors (see below), whose sum is σ = 169343664. Its totient is φ = 141119700.

The previous prime is 155231651. The next prime is 155231683. The reversal of 155231681 is 186132551.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 155231681 - 2¹⁴ = 155215297 is a prime.

It is a super-2 number, since 2×155231681² = 48193749572171522, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (155231683) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 7055975 + ... + 7055996.

It is an arithmetic number, because the mean of its divisors is an integer number (42335916).

Almost surely, 2^155231681 is an apocalyptic number.

155231681 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

155231681 is a deficient number, since it is larger than the sum of its proper divisors (14111983).

155231681 is a wasteful number, since it uses less digits than its factorization.

155231681 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14111982.

The product of its digits is 7200, while the sum is 32.

The square root of 155231681 is about 12459.2006565429. The cubic root of 155231681 is about 537.4360404154.

It can be divided in two parts, 1552 and 31681, that added together give a palindrome (33233).

The spelling of 155231681 in words is "one hundred fifty-five million, two hundred thirty-one thousand, six hundred eighty-one".