51491101 has 2 divisors, whose sum is σ = 51491102. Its totient is φ = 51491100.

The previous prime is 51491059. The next prime is 51491119. The reversal of 51491101 is 10119415.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 30239001 + 21252100 = 5499^2 + 4610^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-51491101 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (51491191) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 25745550 + 25745551.

It is an arithmetic number, because the mean of its divisors is an integer number (25745551).

Almost surely, 2^51491101 is an apocalyptic number.

It is an amenable number.

51491101 is a deficient number, since it is larger than the sum of its proper divisors (1).

51491101 is an equidigital number, since it uses as much as digits as its factorization.

51491101 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 180, while the sum is 22.

The square root of 51491101 is about 7175.7299977076. The cubic root of 51491101 is about 372.0295121497.

The spelling of 51491101 in words is "fifty-one million, four hundred ninety-one thousand, one hundred one".