781000243 has 4 divisors (see below), whose sum is σ = 781496440. Its totient is φ = 780504048.

The previous prime is 781000229. The next prime is 781000249. The reversal of 781000243 is 342000187.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 342000187 = 139 ⋅2460433.

It is a cyclic number.

It is not a de Polignac number, because 781000243 - 2²¹ = 778903091 is a prime.

It is a super-2 number, since 2×781000243² = 1219922759132118098, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (781000249) 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, 245730 + ... + 248887.

It is an arithmetic number, because the mean of its divisors is an integer number (195374110).

Almost surely, 2^781000243 is an apocalyptic number.

781000243 is a deficient number, since it is larger than the sum of its proper divisors (496197).

781000243 is a wasteful number, since it uses less digits than its factorization.

781000243 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 496196.

The product of its (nonzero) digits is 1344, while the sum is 25.

The square root of 781000243 is about 27946.3815725757. The cubic root of 781000243 is about 920.9097188497.

The spelling of 781000243 in words is "seven hundred eighty-one million, two hundred forty-three", and thus it is an aban number.