155222521 has 2 divisors, whose sum is σ = 155222522. Its totient is φ = 155222520.

The previous prime is 155222519. The next prime is 155222527. The reversal of 155222521 is 125222551.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 126450025 + 28772496 = 11245^2 + 5364^2 .

It is a cyclic number.

It is not a de Polignac number, because 155222521 - 2¹ = 155222519 is a prime.

Together with 155222519, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (155222527) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 77611260 + 77611261.

It is an arithmetic number, because the mean of its divisors is an integer number (77611261).

Almost surely, 2^155222521 is an apocalyptic number.

It is an amenable number.

155222521 is a deficient number, since it is larger than the sum of its proper divisors (1).

155222521 is an equidigital number, since it uses as much as digits as its factorization.

155222521 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2000, while the sum is 25.

The square root of 155222521 is about 12458.8330512934. The cubic root of 155222521 is about 537.4254690962.

The spelling of 155222521 in words is "one hundred fifty-five million, two hundred twenty-two thousand, five hundred twenty-one".