47778781 has 4 divisors (see below), whose sum is σ = 49320064. Its totient is φ = 46237500.

The previous prime is 47778779. The next prime is 47778793. The reversal of 47778781 is 18787774.

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 47778781 - 2¹ = 47778779 is a prime.

It is a super-2 number, since 2×47778781² = 4565623827691922, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (47778761) 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, 770595 + ... + 770656.

It is an arithmetic number, because the mean of its divisors is an integer number (12330016).

Almost surely, 2^47778781 is an apocalyptic number.

It is an amenable number.

47778781 is a deficient number, since it is larger than the sum of its proper divisors (1541283).

47778781 is a wasteful number, since it uses less digits than its factorization.

47778781 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1541282.

The product of its digits is 614656, while the sum is 49.

The square root of 47778781 is about 6912.2196869023. The cubic root of 47778781 is about 362.8649508888.

The spelling of 47778781 in words is "forty-seven million, seven hundred seventy-eight thousand, seven hundred eighty-one".