678267921 has 16 divisors (see below), whose sum is σ = 990576000. Its totient is φ = 410903808.

The previous prime is 678267911. The next prime is 678267929. The reversal of 678267921 is 129762876.

It is not a de Polignac number, because 678267921 - 2¹⁴ = 678251537 is a prime.

It is not an unprimeable number, because it can be changed into a prime (678267929) 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, 227821 + ... + 230778.

It is an arithmetic number, because the mean of its divisors is an integer number (61911000).

Almost surely, 2^678267921 is an apocalyptic number.

It is an amenable number.

678267921 is a deficient number, since it is larger than the sum of its proper divisors (312308079).

678267921 is a wasteful number, since it uses less digits than its factorization.

678267921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 458648.

The product of its digits is 508032, while the sum is 48.

The square root of 678267921 is about 26043.5773464399. The cubic root of 678267921 is about 878.6186666234.

The spelling of 678267921 in words is "six hundred seventy-eight million, two hundred sixty-seven thousand, nine hundred twenty-one".