51490685 has 4 divisors (see below), whose sum is σ = 61788828. Its totient is φ = 41192544.

The previous prime is 51490667. The next prime is 51490697. The reversal of 51490685 is 58609415.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 58609415 = 5 ⋅11721883.

It can be written as a sum of positive squares in 2 ways, for example, as 21141604 + 30349081 = 4598^2 + 5509^2 .

It is a cyclic number.

It is not a de Polignac number, because 51490685 - 2¹⁰ = 51489661 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5149064 + ... + 5149073.

It is an arithmetic number, because the mean of its divisors is an integer number (15447207).

Almost surely, 2^51490685 is an apocalyptic number.

It is an amenable number.

51490685 is a deficient number, since it is larger than the sum of its proper divisors (10298143).

51490685 is a wasteful number, since it uses less digits than its factorization.

51490685 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10298142.

The product of its (nonzero) digits is 43200, while the sum is 38.

The square root of 51490685 is about 7175.7010110511. The cubic root of 51490685 is about 372.0285102634.

The spelling of 51490685 in words is "fifty-one million, four hundred ninety thousand, six hundred eighty-five".