623047781 has 4 divisors (see below), whose sum is σ = 629471052. Its totient is φ = 616624512.

The previous prime is 623047757. The next prime is 623047783. The reversal of 623047781 is 187740326.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 187740326 = 2 ⋅93870163.

It can be written as a sum of positive squares in 2 ways, for example, as 272085025 + 350962756 = 16495^2 + 18734^2 .

It is a cyclic number.

It is not a de Polignac number, because 623047781 - 2¹⁰ = 623046757 is a prime.

It is a super-2 number, since 2×623047781² = 776377074818047922, 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 (623047783) 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, 3211490 + ... + 3211683.

It is an arithmetic number, because the mean of its divisors is an integer number (157367763).

Almost surely, 2^623047781 is an apocalyptic number.

It is an amenable number.

623047781 is a deficient number, since it is larger than the sum of its proper divisors (6423271).

623047781 is an equidigital number, since it uses as much as digits as its factorization.

623047781 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6423270.

The product of its (nonzero) digits is 56448, while the sum is 38.

The square root of 623047781 is about 24960.9250830173. The cubic root of 623047781 is about 854.0968455237.

The spelling of 623047781 in words is "six hundred twenty-three million, forty-seven thousand, seven hundred eighty-one".