155864181561 has 8 divisors (see below), whose sum is σ = 226711536864. Its totient is φ = 94463140320.

The previous prime is 155864181559. The next prime is 155864181589. The reversal of 155864181561 is 165181468551.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 155864181561 - 2¹ = 155864181559 is a prime.

It is not an unprimeable number, because it can be changed into a prime (155864181511) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2361578476 + ... + 2361578541.

It is an arithmetic number, because the mean of its divisors is an integer number (28338942108).

Almost surely, 2^155864181561 is an apocalyptic number.

155864181561 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

155864181561 is a deficient number, since it is larger than the sum of its proper divisors (70847355303).

155864181561 is a wasteful number, since it uses less digits than its factorization.

155864181561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4723157031.

The product of its digits is 1152000, while the sum is 51.

The spelling of 155864181561 in words is "one hundred fifty-five billion, eight hundred sixty-four million, one hundred eighty-one thousand, five hundred sixty-one".