155890081 has 2 divisors, whose sum is σ = 155890082. Its totient is φ = 155890080.

The previous prime is 155890069. The next prime is 155890123. The reversal of 155890081 is 180098551.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 92544400 + 63345681 = 9620^2 + 7959^2 .

It is an emirp because it is prime and its reverse (180098551) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 155890081 - 2¹³ = 155881889 is a prime.

It is a super-2 number, since 2×155890081² = 48603434708373122, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 155890081.

It is not a weakly prime, because it can be changed into another prime (155890001) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 77945040 + 77945041.

It is an arithmetic number, because the mean of its divisors is an integer number (77945041).

Almost surely, 2^155890081 is an apocalyptic number.

It is an amenable number.

155890081 is a deficient number, since it is larger than the sum of its proper divisors (1).

155890081 is an equidigital number, since it uses as much as digits as its factorization.

155890081 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 14400, while the sum is 37.

The square root of 155890081 is about 12485.5949397696. The cubic root of 155890081 is about 538.1947961707.

The spelling of 155890081 in words is "one hundred fifty-five million, eight hundred ninety thousand, eighty-one".