51276991 has 4 divisors (see below), whose sum is σ = 53975800. Its totient is φ = 48578184.

The previous prime is 51276989. The next prime is 51276997. The reversal of 51276991 is 19967215.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 19967215 = 5 ⋅3993443.

It is a cyclic number.

It is not a de Polignac number, because 51276991 - 2¹ = 51276989 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 (51276997) 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, 1349376 + ... + 1349413.

It is an arithmetic number, because the mean of its divisors is an integer number (13493950).

Almost surely, 2^51276991 is an apocalyptic number.

51276991 is a deficient number, since it is larger than the sum of its proper divisors (2698809).

51276991 is a wasteful number, since it uses less digits than its factorization.

51276991 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2698808.

The product of its digits is 34020, while the sum is 40.

The square root of 51276991 is about 7160.7954167117. The cubic root of 51276991 is about 371.5131387675.

The spelling of 51276991 in words is "fifty-one million, two hundred seventy-six thousand, nine hundred ninety-one".