51471649 has 2 divisors, whose sum is σ = 51471650. Its totient is φ = 51471648.

The previous prime is 51471647. The next prime is 51471661. The reversal of 51471649 is 94617415.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 34398225 + 17073424 = 5865^2 + 4132^2 .

It is a cyclic number.

It is not a de Polignac number, because 51471649 - 2¹ = 51471647 is a prime.

Together with 51471647, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (51471647) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 25735824 + 25735825.

It is an arithmetic number, because the mean of its divisors is an integer number (25735825).

Almost surely, 2^51471649 is an apocalyptic number.

It is an amenable number.

51471649 is a deficient number, since it is larger than the sum of its proper divisors (1).

51471649 is an equidigital number, since it uses as much as digits as its factorization.

51471649 is an evil number, because the sum of its binary digits is even.

The product of its digits is 30240, while the sum is 37.

The square root of 51471649 is about 7174.3744675059. The cubic root of 51471649 is about 371.9826585549.

The spelling of 51471649 in words is "fifty-one million, four hundred seventy-one thousand, six hundred forty-nine".