51420505 has 4 divisors (see below), whose sum is σ = 61704612. Its totient is φ = 41136400.

The previous prime is 51420503. The next prime is 51420511. The reversal of 51420505 is 50502415.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 35952016 + 15468489 = 5996^2 + 3933^2 .

It is not a de Polignac number, because 51420505 - 2¹ = 51420503 is a prime.

It is a Smith number, since the sum of its digits (22) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (51420503) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5142046 + ... + 5142055.

It is an arithmetic number, because the mean of its divisors is an integer number (15426153).

Almost surely, 2^51420505 is an apocalyptic number.

It is an amenable number.

51420505 is a deficient number, since it is larger than the sum of its proper divisors (10284107).

51420505 is a wasteful number, since it uses less digits than its factorization.

51420505 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10284106.

The product of its (nonzero) digits is 1000, while the sum is 22.

The square root of 51420505 is about 7170.8092290898. The cubic root of 51420505 is about 371.8594128062.

The spelling of 51420505 in words is "fifty-one million, four hundred twenty thousand, five hundred five".