155865536790544 has 75 divisors (see below), whose sum is σ = 352305625324317. Its totient is φ = 66798467059968.

The previous prime is 155865536790461. The next prime is 155865536790547. The reversal of 155865536790544 is 445097635568551.

The square root of 155865536790544 is 12484612.

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

It can be written as a sum of positive squares in only one way, i.e., 6627844291600 + 149237692498944 = 2574460^2 + 12216288^2 .

It is not an unprimeable number, because it can be changed into a prime (155865536790547) by changing a digit.

It is a polite number, since it can be written in 14 ways as a sum of consecutive naturals, for example, 2446952104 + ... + 2447015800.

Almost surely, 2^{155865536790544} is an apocalyptic number.

155865536790544 is a gapful number since it is divisible by the number (14) formed by its first and last digit.

155865536790544 is the 12484612-nd square number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 155865536790544

155865536790544 is an abundant number, since it is smaller than the sum of its proper divisors (196440088533773).

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

155865536790544 is an frugal number, since it uses more digits than its factorization.

155865536790544 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 127430 (or 63706 counting only the distinct ones).

The product of its (nonzero) digits is 2721600000, while the sum is 73.

The spelling of 155865536790544 in words is "one hundred fifty-five trillion, eight hundred sixty-five billion, five hundred thirty-six million, seven hundred ninety thousand, five hundred forty-four".