51521345 has 4 divisors (see below), whose sum is σ = 61825620. Its totient is φ = 41217072.

The previous prime is 51521329. The next prime is 51521359. The reversal of 51521345 is 54312515.

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

It can be written as a sum of positive squares in 2 ways, for example, as 41049649 + 10471696 = 6407^2 + 3236^2 .

It is a cyclic number.

It is not a de Polignac number, because 51521345 - 2⁴ = 51521329 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5152130 + ... + 5152139.

It is an arithmetic number, because the mean of its divisors is an integer number (15456405).

Almost surely, 2^51521345 is an apocalyptic number.

It is an amenable number.

51521345 is a deficient number, since it is larger than the sum of its proper divisors (10304275).

51521345 is a wasteful number, since it uses less digits than its factorization.

51521345 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10304274.

The product of its digits is 3000, while the sum is 26.

The square root of 51521345 is about 7177.8370697585. The cubic root of 51521345 is about 372.1023367616.

The spelling of 51521345 in words is "fifty-one million, five hundred twenty-one thousand, three hundred forty-five".