155891869 has 4 divisors (see below), whose sum is σ = 178162144. Its totient is φ = 133621596.

The previous prime is 155891867. The next prime is 155891927. The reversal of 155891869 is 968198551.

155891869 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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, and also an emirpimes, since its reverse is a distinct semiprime: 968198551 = 3581 ⋅270371.

It is a cyclic number.

It is not a de Polignac number, because 155891869 - 2¹ = 155891867 is a prime.

It is a super-2 number, since 2×155891869² = 48604549640626322, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (155891863) 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, 11135127 + ... + 11135140.

It is an arithmetic number, because the mean of its divisors is an integer number (44540536).

Almost surely, 2^155891869 is an apocalyptic number.

It is an amenable number.

155891869 is a deficient number, since it is larger than the sum of its proper divisors (22270275).

155891869 is an equidigital number, since it uses as much as digits as its factorization.

155891869 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22270274.

The product of its digits is 777600, while the sum is 52.

The square root of 155891869 is about 12485.6665420794. Note that the first 3 decimals coincide. The cubic root of 155891869 is about 538.1968537928.

The spelling of 155891869 in words is "one hundred fifty-five million, eight hundred ninety-one thousand, eight hundred sixty-nine".