155377681 has 4 divisors (see below), whose sum is σ = 156044772. Its totient is φ = 154710592.

The previous prime is 155377669. The next prime is 155377709. The reversal of 155377681 is 186773551.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 186773551 = 5783 ⋅32297.

It can be written as a sum of positive squares in 2 ways, for example, as 43441281 + 111936400 = 6591^2 + 10580^2 .

It is a cyclic number.

It is not a de Polignac number, because 155377681 - 2⁹ = 155377169 is a prime.

It is a super-2 number, since 2×155377681² = 48284447505875522, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (155377661) 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, 333196 + ... + 333661.

It is an arithmetic number, because the mean of its divisors is an integer number (39011193).

Almost surely, 2^155377681 is an apocalyptic number.

It is an amenable number.

155377681 is a deficient number, since it is larger than the sum of its proper divisors (667091).

155377681 is an equidigital number, since it uses as much as digits as its factorization.

155377681 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 667090.

The product of its digits is 176400, while the sum is 43.

The square root of 155377681 is about 12465.0584033931. The cubic root of 155377681 is about 537.6044791312.

The spelling of 155377681 in words is "one hundred fifty-five million, three hundred seventy-seven thousand, six hundred eighty-one".