155781951 has 32 divisors (see below), whose sum is σ = 232505280. Its totient is φ = 92150784.

The previous prime is 155781949. The next prime is 155781959. The reversal of 155781951 is 159187551.

155781951 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 155781951 - 2¹ = 155781949 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (155781959) 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, 127821 + ... + 129033.

It is an arithmetic number, because the mean of its divisors is an integer number (7265790).

Almost surely, 2^155781951 is an apocalyptic number.

155781951 is a deficient number, since it is larger than the sum of its proper divisors (76723329).

155781951 is a wasteful number, since it uses less digits than its factorization.

155781951 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1355.

The product of its digits is 63000, while the sum is 42.

The square root of 155781951 is about 12481.2639984899. The cubic root of 155781951 is about 538.0703314124.

The spelling of 155781951 in words is "one hundred fifty-five million, seven hundred eighty-one thousand, nine hundred fifty-one".