47640781 has 4 divisors (see below), whose sum is σ = 47754364. Its totient is φ = 47527200.

The previous prime is 47640773. The next prime is 47640821. The reversal of 47640781 is 18704674.

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 17015625 + 30625156 = 4125^2 + 5534^2 .

It is a cyclic number.

It is not a de Polignac number, because 47640781 - 2³ = 47640773 is a prime.

It is a super-2 number, since 2×47640781² = 4539288028579922, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 47640781.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (47640701) 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, 56160 + ... + 57001.

It is an arithmetic number, because the mean of its divisors is an integer number (11938591).

Almost surely, 2^47640781 is an apocalyptic number.

It is an amenable number.

47640781 is a deficient number, since it is larger than the sum of its proper divisors (113583).

47640781 is a wasteful number, since it uses less digits than its factorization.

47640781 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 113582.

The product of its (nonzero) digits is 37632, while the sum is 37.

The square root of 47640781 is about 6902.2301468438. The cubic root of 47640781 is about 362.5152583351.

The spelling of 47640781 in words is "forty-seven million, six hundred forty thousand, seven hundred eighty-one".