51009901 has 4 divisors (see below), whose sum is σ = 51190432. Its totient is φ = 50829372.

The previous prime is 51009887. The next prime is 51009941. The reversal of 51009901 is 10990015.

51009901 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 10990015 = 5 ⋅2198003.

It is a cyclic number.

It is not a de Polignac number, because 51009901 - 2⁷ = 51009773 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51009941) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 89841 + ... + 90406.

It is an arithmetic number, because the mean of its divisors is an integer number (12797608).

Almost surely, 2^51009901 is an apocalyptic number.

It is an amenable number.

51009901 is a deficient number, since it is larger than the sum of its proper divisors (180531).

51009901 is a wasteful number, since it uses less digits than its factorization.

51009901 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 180530.

The product of its (nonzero) digits is 405, while the sum is 25.

The square root of 51009901 is about 7142.1216035573. The cubic root of 51009901 is about 370.8669735197.

Adding to 51009901 its reverse (10990015), we get a palindrome (61999916).

The spelling of 51009901 in words is "fifty-one million, nine thousand, nine hundred one".