51691061 has 2 divisors, whose sum is σ = 51691062. Its totient is φ = 51691060.

The previous prime is 51691019. The next prime is 51691069. The reversal of 51691061 is 16019615.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 37136836 + 14554225 = 6094^2 + 3815^2 .

It is a cyclic number.

It is not a de Polignac number, because 51691061 - 2¹⁴ = 51674677 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (51691069) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 25845530 + 25845531.

It is an arithmetic number, because the mean of its divisors is an integer number (25845531).

Almost surely, 2^51691061 is an apocalyptic number.

It is an amenable number.

51691061 is a deficient number, since it is larger than the sum of its proper divisors (1).

51691061 is an equidigital number, since it uses as much as digits as its factorization.

51691061 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1620, while the sum is 29.

The square root of 51691061 is about 7189.6495742143. The cubic root of 51691061 is about 372.5104686036.

The spelling of 51691061 in words is "fifty-one million, six hundred ninety-one thousand, sixty-one".