155221314520 has 128 divisors (see below), whose sum is σ = 386874351360. Its totient is φ = 55797514240.

The previous prime is 155221314481. The next prime is 155221314533. The reversal of 155221314520 is 25413122551.

155221314520 = 23753² + 23754² + ... + 24024².

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1251132 + ... + 1369588.

It is an arithmetic number, because the mean of its divisors is an integer number (3022455870).

Almost surely, 2^155221314520 is an apocalyptic number.

155221314520 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 155221314520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (193437175680).

155221314520 is an abundant number, since it is smaller than the sum of its proper divisors (231653036840).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

155221314520 is a wasteful number, since it uses less digits than its factorization.

155221314520 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 118573 (or 118569 counting only the distinct ones).

The product of its (nonzero) digits is 12000, while the sum is 31.

The spelling of 155221314520 in words is "one hundred fifty-five billion, two hundred twenty-one million, three hundred fourteen thousand, five hundred twenty".