155421235225 has 27 divisors (see below), whose sum is σ = 198164810781. Its totient is φ = 120919759200.

The previous prime is 155421235213. The next prime is 155421235301. The reversal of 155421235225 is 522532124551.

The square root of 155421235225 is 394235.

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

155421235225 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 4 ways, for example, as 14754232089 + 140667003136 = 121467^2 + 375056^2 .

It is not a de Polignac number, because 155421235225 - 2²⁵ = 155387680793 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (37).

It is a Duffinian number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 72932410 + ... + 72934540.

Almost surely, 2^155421235225 is an apocalyptic number.

155421235225 is the 394235-th square number.

155421235225 is the 197118-th centered octagonal number.

It is an amenable number.

155421235225 is a deficient number, since it is larger than the sum of its proper divisors (42743575556).

155421235225 is an frugal number, since it uses more digits than its factorization.

155421235225 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4346 (or 2173 counting only the distinct ones).

The product of its digits is 120000, while the sum is 37.

Adding to 155421235225 its reverse (522532124551), we get a palindrome (677953359776).

The spelling of 155421235225 in words is "one hundred fifty-five billion, four hundred twenty-one million, two hundred thirty-five thousand, two hundred twenty-five".