781145431 has 4 divisors (see below), whose sum is σ = 852158664. Its totient is φ = 710132200.

The previous prime is 781145381. The next prime is 781145441. The reversal of 781145431 is 134541187.

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 781145431 - 2¹⁹ = 780621143 is a prime.

It is a super-2 number, since 2×781145431² = 1220376368744351522, 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 (781145441) 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, 35506600 + ... + 35506621.

It is an arithmetic number, because the mean of its divisors is an integer number (213039666).

Almost surely, 2^781145431 is an apocalyptic number.

781145431 is a deficient number, since it is larger than the sum of its proper divisors (71013233).

781145431 is a wasteful number, since it uses less digits than its factorization.

781145431 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 71013232.

The product of its digits is 13440, while the sum is 34.

The square root of 781145431 is about 27948.9790690107. The cubic root of 781145431 is about 920.9667810410.

The spelling of 781145431 in words is "seven hundred eighty-one million, one hundred forty-five thousand, four hundred thirty-one".