781998455 has 16 divisors (see below), whose sum is σ = 1095275520. Its totient is φ = 524817312.

The previous prime is 781998443. The next prime is 781998457. The reversal of 781998455 is 554899187.

It is a cyclic number.

It is not a de Polignac number, because 781998455 - 2⁴ = 781998439 is a prime.

It is a super-2 number, since 2×781998455² = 1223043167244774050, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 781998455.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (781998457) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 236045 + ... + 239334.

It is an arithmetic number, because the mean of its divisors is an integer number (68454720).

Almost surely, 2^781998455 is an apocalyptic number.

781998455 is a deficient number, since it is larger than the sum of its proper divisors (313277065).

781998455 is a wasteful number, since it uses less digits than its factorization.

781998455 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 475438.

The product of its digits is 3628800, while the sum is 56.

The square root of 781998455 is about 27964.2352836619. The cubic root of 781998455 is about 921.3018961785.

The spelling of 781998455 in words is "seven hundred eighty-one million, nine hundred ninety-eight thousand, four hundred fifty-five".