781258401 has 63 divisors (see below), whose sum is σ = 1443999297. Its totient is φ = 405848520.

The previous prime is 781258363. The next prime is 781258417. The reversal of 781258401 is 104852187.

The square root of 781258401 is 27951.

It is a perfect power (a square), and thus also a powerful number.

781258401 is a `hidden beast` number, since 78 + 1 + 2 + 584 + 0 + 1 = 666.

It is a tau number, because it is divible by the number of its divisors (63).

It is not a de Polignac number, because 781258401 - 2⁹ = 781257889 is a prime.

It is a super-2 number, since 2×781258401² = 1220729378266153602, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (781258451) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 62 ways as a sum of consecutive naturals, for example, 71023486 + ... + 71023496.

Almost surely, 2^781258401 is an apocalyptic number.

781258401 is the 27951-st square number.

781258401 is the 13976-th centered octagonal number.

It is an amenable number.

781258401 is a deficient number, since it is larger than the sum of its proper divisors (662740896).

781258401 is an frugal number, since it uses more digits than its factorization.

781258401 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 86 (or 21 counting only the distinct ones).

The product of its (nonzero) digits is 17920, while the sum is 36.

The cubic root of 781258401 is about 921.0111759334.

Multiplying 781258401 by its sum of digits (36), we get a square (28125302436 = 167706²).

The spelling of 781258401 in words is "seven hundred eighty-one million, two hundred fifty-eight thousand, four hundred one".