51516551 has 2 divisors, whose sum is σ = 51516552.
Its totient is φ = 51516550.
The previous prime is 51516539. The next prime is 51516571. The reversal of 51516551 is 15561515.
It is a happy number.
It is a weak prime.
It is a cyclic number.
It is not a de Polignac number, because 51516551 - 214 = 51500167 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 (51516571) by changing a digit.
It is a polite number, since it can be written as a sum of consecutive naturals, namely, 25758275 + 25758276.
It is an arithmetic number, because the mean of its divisors is an integer number (25758276).
Almost surely, 251516551 is an apocalyptic number.
51516551 is a deficient number, since it is larger than the sum of its proper divisors (1).
51516551 is an equidigital number, since it uses as much as digits as its factorization.
51516551 is an evil number, because the sum of its binary digits is even.
The product of its digits is 3750, while the sum is 29.
The square root of 51516551 is about 7177.5031173800.
The cubic root of 51516551 is about 372.0907951767.
The spelling of 51516551 in words is "fifty-one million, five hundred sixteen thousand, five hundred fifty-one".