51020155 has 4 divisors (see below), whose sum is σ = 61224192. Its totient is φ = 40816120.

The previous prime is 51020153. The next prime is 51020161. The reversal of 51020155 is 55102015.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 51020155 - 2¹ = 51020153 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (51020153) 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, 5102011 + ... + 5102020.

It is an arithmetic number, because the mean of its divisors is an integer number (15306048).

Almost surely, 2^51020155 is an apocalyptic number.

51020155 is a deficient number, since it is larger than the sum of its proper divisors (10204037).

51020155 is a wasteful number, since it uses less digits than its factorization.

51020155 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10204036.

The product of its (nonzero) digits is 250, while the sum is 19.

The square root of 51020155 is about 7142.8394214066. The cubic root of 51020155 is about 370.8918223894.

The spelling of 51020155 in words is "fifty-one million, twenty thousand, one hundred fifty-five".