51671491 has 2 divisors, whose sum is σ = 51671492. Its totient is φ = 51671490.

The previous prime is 51671479. The next prime is 51671549. The reversal of 51671491 is 19417615.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-51671491 is a prime.

It is not a weakly prime, because it can be changed into another prime (51671441) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 25835745 + 25835746.

It is an arithmetic number, because the mean of its divisors is an integer number (25835746).

Almost surely, 2^51671491 is an apocalyptic number.

51671491 is a deficient number, since it is larger than the sum of its proper divisors (1).

51671491 is an equidigital number, since it uses as much as digits as its factorization.

51671491 is an evil number, because the sum of its binary digits is even.

The product of its digits is 7560, while the sum is 34.

The square root of 51671491 is about 7188.2884611012. The cubic root of 51671491 is about 372.4634524148.

The spelling of 51671491 in words is "fifty-one million, six hundred seventy-one thousand, four hundred ninety-one".