155251681 has 12 divisors (see below), whose sum is σ = 171294588. Its totient is φ = 140597184.

The previous prime is 155251673. The next prime is 155251687. The reversal of 155251681 is 186152551.

It can be written as a sum of positive squares in 6 ways, for example, as 43230625 + 112021056 = 6575^2 + 10584^2 .

It is not a de Polignac number, because 155251681 - 2³ = 155251673 is a prime.

It is a super-2 number, since 2×155251681² = 48206168906651522, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (155251687) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 291 + ... + 17623.

It is an arithmetic number, because the mean of its divisors is an integer number (14274549).

Almost surely, 2^155251681 is an apocalyptic number.

It is an amenable number.

155251681 is a deficient number, since it is larger than the sum of its proper divisors (16042907).

155251681 is a wasteful number, since it uses less digits than its factorization.

155251681 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17412 (or 17399 counting only the distinct ones).

The product of its digits is 12000, while the sum is 34.

The square root of 155251681 is about 12460.0032504009. The cubic root of 155251681 is about 537.4591204533.

It can be divided in two parts, 1552516 and 81, that multiplied together give a square (125753796 = 11214²).

The spelling of 155251681 in words is "one hundred fifty-five million, two hundred fifty-one thousand, six hundred eighty-one".