781382057 has 4 divisors (see below), whose sum is σ = 785308800. Its totient is φ = 777455316.

The previous prime is 781382053. The next prime is 781382081. The reversal of 781382057 is 750283187.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 781382057 - 2² = 781382053 is a prime.

It is a super-2 number, since 2×781382057² = 1221115838003102498, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (781382053) 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, 1963073 + ... + 1963470.

It is an arithmetic number, because the mean of its divisors is an integer number (196327200).

Almost surely, 2^781382057 is an apocalyptic number.

It is an amenable number.

781382057 is a deficient number, since it is larger than the sum of its proper divisors (3926743).

781382057 is a wasteful number, since it uses less digits than its factorization.

781382057 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3926742.

The product of its (nonzero) digits is 94080, while the sum is 41.

The square root of 781382057 is about 27953.2119263601. The cubic root of 781382057 is about 921.0597652989.

The spelling of 781382057 in words is "seven hundred eighty-one million, three hundred eighty-two thousand, fifty-seven".