155641861 has 4 divisors (see below), whose sum is σ = 155982892. Its totient is φ = 155300832.

The previous prime is 155641859. The next prime is 155641877. The reversal of 155641861 is 168146551.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 145202500 + 10439361 = 12050^2 + 3231^2 .

It is a cyclic number.

It is not a de Polignac number, because 155641861 - 2¹ = 155641859 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 155641861.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (155641061) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 169830 + ... + 170743.

It is an arithmetic number, because the mean of its divisors is an integer number (38995723).

Almost surely, 2^155641861 is an apocalyptic number.

It is an amenable number.

155641861 is a deficient number, since it is larger than the sum of its proper divisors (341031).

155641861 is an equidigital number, since it uses as much as digits as its factorization.

155641861 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 341030.

The product of its digits is 28800, while the sum is 37.

The square root of 155641861 is about 12475.6507245113. The cubic root of 155641861 is about 537.9089929119.

The spelling of 155641861 in words is "one hundred fifty-five million, six hundred forty-one thousand, eight hundred sixty-one".