155220021512425 has 6 divisors (see below), whose sum is σ = 192472826675438. Its totient is φ = 124176017209920.

The previous prime is 155220021512411. The next prime is 155220021512429. The reversal of 155220021512425 is 524215120022551.

It is a happy number.

It can be written as a sum of positive squares in 3 ways, for example, as 3506889961 + 155216514622464 = 59219^2 + 12458592^2 .

It is not a de Polignac number, because 155220021512425 - 2³³ = 155211431577833 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (155220021512429) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 3104400430224 + ... + 3104400430273.

Almost surely, 2^{155220021512425} is an apocalyptic number.

It is an amenable number.

155220021512425 is a deficient number, since it is larger than the sum of its proper divisors (37252805163013).

155220021512425 is an equidigital number, since it uses as much as digits as its factorization.

155220021512425 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6208800860507 (or 6208800860502 counting only the distinct ones).

The product of its (nonzero) digits is 80000, while the sum is 37.

Adding to 155220021512425 its reverse (524215120022551), we get a palindrome (679435141534976).

The spelling of 155220021512425 in words is "one hundred fifty-five trillion, two hundred twenty billion, twenty-one million, five hundred twelve thousand, four hundred twenty-five".