780405947 has 4 divisors (see below), whose sum is σ = 782314440. Its totient is φ = 778497456.

The previous prime is 780405917. The next prime is 780405953. The reversal of 780405947 is 749504087.

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

It is a cyclic number.

It is not a de Polignac number, because 780405947 - 2¹⁰ = 780404923 is a prime.

It is a super-2 number, since 2×780405947² = 1218066884225933618, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 780405898 and 780405907.

It is not an unprimeable number, because it can be changed into a prime (780405917) 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, 953633 + ... + 954450.

It is an arithmetic number, because the mean of its divisors is an integer number (195578610).

Almost surely, 2^780405947 is an apocalyptic number.

780405947 is a deficient number, since it is larger than the sum of its proper divisors (1908493).

780405947 is a wasteful number, since it uses less digits than its factorization.

780405947 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1908492.

The product of its (nonzero) digits is 282240, while the sum is 44.

The square root of 780405947 is about 27935.7467593046. The cubic root of 780405947 is about 920.6760732372.

The spelling of 780405947 in words is "seven hundred eighty million, four hundred five thousand, nine hundred forty-seven".