51545391 has 4 divisors (see below), whose sum is σ = 68727192. Its totient is φ = 34363592.

The previous prime is 51545387. The next prime is 51545393. The reversal of 51545391 is 19354515.

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

It is a cyclic number.

It is not a de Polignac number, because 51545391 - 2² = 51545387 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51545393) 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, 8590896 + ... + 8590901.

It is an arithmetic number, because the mean of its divisors is an integer number (17181798).

Almost surely, 2^51545391 is an apocalyptic number.

51545391 is a deficient number, since it is larger than the sum of its proper divisors (17181801).

51545391 is a wasteful number, since it uses less digits than its factorization.

51545391 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17181800.

The product of its digits is 13500, while the sum is 33.

The square root of 51545391 is about 7179.5118914868. The cubic root of 51545391 is about 372.1602168574.

The spelling of 51545391 in words is "fifty-one million, five hundred forty-five thousand, three hundred ninety-one".