51391245 has 16 divisors (see below), whose sum is σ = 84232512. Its totient is φ = 26739840.

The previous prime is 51391243. The next prime is 51391271. The reversal of 51391245 is 54219315.

It is not a de Polignac number, because 51391245 - 2¹ = 51391243 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51391243) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 41167 + ... + 42396.

It is an arithmetic number, because the mean of its divisors is an integer number (5264532).

Almost surely, 2^51391245 is an apocalyptic number.

It is an amenable number.

51391245 is a deficient number, since it is larger than the sum of its proper divisors (32841267).

51391245 is a wasteful number, since it uses less digits than its factorization.

51391245 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 83612.

The product of its digits is 5400, while the sum is 30.

The square root of 51391245 is about 7168.7687227306. The cubic root of 51391245 is about 371.7888659113.

The spelling of 51391245 in words is "fifty-one million, three hundred ninety-one thousand, two hundred forty-five".