155012421 has 4 divisors (see below), whose sum is σ = 206683232. Its totient is φ = 103341612.

The previous prime is 155012419. The next prime is 155012423. The reversal of 155012421 is 124210551.

155012421 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is an interprime number because it is at equal distance from previous prime (155012419) and next prime (155012423).

It is not a de Polignac number, because 155012421 - 2¹ = 155012419 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (155012423) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 25835401 + ... + 25835406.

It is an arithmetic number, because the mean of its divisors is an integer number (51670808).

Almost surely, 2^155012421 is an apocalyptic number.

It is an amenable number.

155012421 is a deficient number, since it is larger than the sum of its proper divisors (51670811).

155012421 is an equidigital number, since it uses as much as digits as its factorization.

155012421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 51670810.

The product of its (nonzero) digits is 400, while the sum is 21.

The square root of 155012421 is about 12450.3984273597. The cubic root of 155012421 is about 537.1828838647.

Adding to 155012421 its reverse (124210551), we get a palindrome (279222972).

The spelling of 155012421 in words is "one hundred fifty-five million, twelve thousand, four hundred twenty-one".