423738781 has 4 divisors (see below), whose sum is σ = 424024092. Its totient is φ = 423453472.

The previous prime is 423738751. The next prime is 423738797. The reversal of 423738781 is 187837324.

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 149670756 + 274068025 = 12234^2 + 16555^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-423738781 is a prime.

It is a super-2 number, since 2×423738781² = 359109109046731922, 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 (423738751) 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, 140416 + ... + 143401.

It is an arithmetic number, because the mean of its divisors is an integer number (106006023).

Almost surely, 2^423738781 is an apocalyptic number.

It is an amenable number.

423738781 is a deficient number, since it is larger than the sum of its proper divisors (285311).

423738781 is a wasteful number, since it uses less digits than its factorization.

423738781 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 285310.

The product of its digits is 225792, while the sum is 43.

The square root of 423738781 is about 20584.9163466845. The cubic root of 423738781 is about 751.1028403442.

The spelling of 423738781 in words is "four hundred twenty-three million, seven hundred thirty-eight thousand, seven hundred eighty-one".