804778551 has 16 divisors (see below), whose sum is σ = 1211812320. Its totient is φ = 527722560.

The previous prime is 804778547. The next prime is 804778561. The reversal of 804778551 is 155877408.

It is a happy number.

It is not a de Polignac number, because 804778551 - 2² = 804778547 is a prime.

It is a super-2 number, since 2×804778551² = 1295337032299319202, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 804778497 and 804778506.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (804778561) 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, 242670 + ... + 245963.

It is an arithmetic number, because the mean of its divisors is an integer number (75738270).

Almost surely, 2^804778551 is an apocalyptic number.

804778551 is a deficient number, since it is larger than the sum of its proper divisors (407033769).

804778551 is a wasteful number, since it uses less digits than its factorization.

804778551 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 488703 (or 488697 counting only the distinct ones).

The product of its (nonzero) digits is 313600, while the sum is 45.

The square root of 804778551 is about 28368.6191239546. The cubic root of 804778551 is about 930.1624378073.

The spelling of 804778551 in words is "eight hundred four million, seven hundred seventy-eight thousand, five hundred fifty-one".