51217971 has 16 divisors (see below), whose sum is σ = 78403584. Its totient is φ = 29133504.

The previous prime is 51217967. The next prime is 51217993. The reversal of 51217971 is 17971215.

It is not a de Polignac number, because 51217971 - 2² = 51217967 is a prime.

It is not an unprimeable number, because it can be changed into a prime (51217951) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 786 + ... + 10151.

It is an arithmetic number, because the mean of its divisors is an integer number (4900224).

Almost surely, 2^51217971 is an apocalyptic number.

51217971 is a deficient number, since it is larger than the sum of its proper divisors (27185613).

51217971 is a wasteful number, since it uses less digits than its factorization.

51217971 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11170.

The product of its digits is 4410, while the sum is 33.

The square root of 51217971 is about 7156.6731796275. The cubic root of 51217971 is about 371.3705463950.

Adding to 51217971 its product of digits (4410), we get a triangular number (51222381 = T₁₀₁₂₁).

Subtracting from 51217971 its reverse (17971215), we obtain a square (33246756 = 5766²).

The spelling of 51217971 in words is "fifty-one million, two hundred seventeen thousand, nine hundred seventy-one".