155463815521 has 81 divisors (see below), whose sum is σ = 197849531313. Its totient is φ = 121787986320.

The previous prime is 155463815519. The next prime is 155463815561. The reversal of 155463815521 is 125518364551.

The square root of 155463815521 is 394289.

It is a perfect power (a square), and thus also a powerful number.

It is not a de Polignac number, because 155463815521 - 2¹ = 155463815519 is a prime.

It is not an unprimeable number, because it can be changed into a prime (155463815561) by changing a digit.

It is a polite number, since it can be written in 80 ways as a sum of consecutive naturals, for example, 1967896360 + ... + 1967896438.

Almost surely, 2^155463815521 is an apocalyptic number.

155463815521 is the 394289-th square number.

155463815521 is the 197145-th centered octagonal number.

It is an amenable number.

155463815521 is a deficient number, since it is larger than the sum of its proper divisors (42385715792).

155463815521 is an frugal number, since it uses more digits than its factorization.

155463815521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 280 (or 140 counting only the distinct ones).

The product of its digits is 720000, while the sum is 46.

The spelling of 155463815521 in words is "one hundred fifty-five billion, four hundred sixty-three million, eight hundred fifteen thousand, five hundred twenty-one".