781408401 has 4 divisors (see below), whose sum is σ = 1041877872. Its totient is φ = 520938932.

The previous prime is 781408391. The next prime is 781408409. The reversal of 781408401 is 104804187.

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, and also an emirpimes, since its reverse is a distinct semiprime: 104804187 = 3 ⋅34934729.

It is a cyclic number.

It is not a de Polignac number, because 781408401 - 2⁷ = 781408273 is a prime.

It is a super-2 number, since 2×781408401² = 1221198178306753602, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (781408409) 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, 130234731 + ... + 130234736.

It is an arithmetic number, because the mean of its divisors is an integer number (260469468).

Almost surely, 2^781408401 is an apocalyptic number.

It is an amenable number.

781408401 is a deficient number, since it is larger than the sum of its proper divisors (260469471).

781408401 is a wasteful number, since it uses less digits than its factorization.

781408401 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 260469470.

The product of its (nonzero) digits is 7168, while the sum is 33.

The square root of 781408401 is about 27953.6831383630. The cubic root of 781408401 is about 921.0701162429.

The spelling of 781408401 in words is "seven hundred eighty-one million, four hundred eight thousand, four hundred one".