5209781 has 4 divisors (see below), whose sum is σ = 5484000. Its totient is φ = 4935564.

The previous prime is 5209777. The next prime is 5209783. The reversal of 5209781 is 1879025.

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.

It is a cyclic number.

It is not a de Polignac number, because 5209781 - 2² = 5209777 is a prime.

It is a super-2 number, since 2×5209781² = 54283636135922, which contains 22 as substring.

It is a Duffinian number.

It is a nialpdrome in base 14.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (5209783) 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, 137081 + ... + 137118.

It is an arithmetic number, because the mean of its divisors is an integer number (1371000).

Almost surely, 2^5209781 is an apocalyptic number.

It is an amenable number.

5209781 is a deficient number, since it is larger than the sum of its proper divisors (274219).

5209781 is a wasteful number, since it uses less digits than its factorization.

5209781 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 274218.

The product of its (nonzero) digits is 5040, while the sum is 32.

The square root of 5209781 is about 2282.4944687775. The cubic root of 5209781 is about 173.3563771960.

It can be divided in two parts, 520 and 9781, that added together give a palindrome (10301).

The spelling of 5209781 in words is "five million, two hundred nine thousand, seven hundred eighty-one".