155561521465 has 64 divisors (see below), whose sum is σ = 221992648704. Its totient is φ = 102428644608.

The previous prime is 155561521459. The next prime is 155561521469. The reversal of 155561521465 is 564125165551.

It is a cyclic number.

It is not a de Polignac number, because 155561521465 - 2³³ = 146971586873 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (155561521469) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 39211912 + ... + 39215878.

It is an arithmetic number, because the mean of its divisors is an integer number (3468635136).

Almost surely, 2^155561521465 is an apocalyptic number.

It is an amenable number.

155561521465 is a deficient number, since it is larger than the sum of its proper divisors (66431127239).

155561521465 is a wasteful number, since it uses less digits than its factorization.

155561521465 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4406.

The product of its digits is 900000, while the sum is 46.

The spelling of 155561521465 in words is "one hundred fifty-five billion, five hundred sixty-one million, five hundred twenty-one thousand, four hundred sixty-five".