51211591 has 8 divisors (see below), whose sum is σ = 51891840. Its totient is φ = 50535288.

The previous prime is 51211577. The next prime is 51211603. The reversal of 51211591 is 19511215.

It is a happy number.

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

It is a cyclic number.

It is not a de Polignac number, because 51211591 - 2⁹ = 51211079 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51211541) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 32070 + ... + 33628.

It is an arithmetic number, because the mean of its divisors is an integer number (6486480).

Almost surely, 2^51211591 is an apocalyptic number.

51211591 is a deficient number, since it is larger than the sum of its proper divisors (680249).

51211591 is a wasteful number, since it uses less digits than its factorization.

51211591 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1973.

The product of its digits is 450, while the sum is 25.

The square root of 51211591 is about 7156.2274279120. The cubic root of 51211591 is about 371.3551257498.

The spelling of 51211591 in words is "fifty-one million, two hundred eleven thousand, five hundred ninety-one".