51390245 has 8 divisors (see below), whose sum is σ = 61712280. Its totient is φ = 41082880.

The previous prime is 51390221. The next prime is 51390263. The reversal of 51390245 is 54209315.

It can be written as a sum of positive squares in 4 ways, for example, as 8958049 + 42432196 = 2993^2 + 6514^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 51390245 - 2⁶ = 51390181 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 6725 + ... + 12165.

It is an arithmetic number, because the mean of its divisors is an integer number (7714035).

Almost surely, 2^51390245 is an apocalyptic number.

It is an amenable number.

51390245 is a deficient number, since it is larger than the sum of its proper divisors (10322035).

51390245 is a wasteful number, since it uses less digits than its factorization.

51390245 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7335.

The product of its (nonzero) digits is 5400, while the sum is 29.

The square root of 51390245 is about 7168.6989754069. The cubic root of 51390245 is about 371.7864544028.

The spelling of 51390245 in words is "fifty-one million, three hundred ninety thousand, two hundred forty-five".