51309905 has 8 divisors (see below), whose sum is σ = 62057472. Its totient is φ = 40724208.

The previous prime is 51309889. The next prime is 51309911. The reversal of 51309905 is 50990315.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 51309905 - 2⁴ = 51309889 is a prime.

It is a super-2 number, since 2×51309905² = 5265412702218050, which contains 22 as substring.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 39767 + ... + 41036.

It is an arithmetic number, because the mean of its divisors is an integer number (7757184).

Almost surely, 2^51309905 is an apocalyptic number.

It is an amenable number.

51309905 is a deficient number, since it is larger than the sum of its proper divisors (10747567).

51309905 is a wasteful number, since it uses less digits than its factorization.

51309905 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 80935.

The product of its (nonzero) digits is 6075, while the sum is 32.

The square root of 51309905 is about 7163.0932564082. The cubic root of 51309905 is about 371.5926115019.

The spelling of 51309905 in words is "fifty-one million, three hundred nine thousand, nine hundred five".