21969678 has 16 divisors (see below), whose sum is σ = 46524240. Its totient is φ = 6892416.

The previous prime is 21969677. The next prime is 21969691. The reversal of 21969678 is 87696912.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21969671) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 107593 + ... + 107796.

It is an arithmetic number, because the mean of its divisors is an integer number (2907765).

Almost surely, 2^21969678 is an apocalyptic number.

21969678 is an abundant number, since it is smaller than the sum of its proper divisors (24554562).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21969678 is a wasteful number, since it uses less digits than its factorization.

21969678 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 215411.

The product of its digits is 326592, while the sum is 48.

The square root of 21969678 is about 4687.1823092344. The cubic root of 21969678 is about 280.0751413977.

The spelling of 21969678 in words is "twenty-one million, nine hundred sixty-nine thousand, six hundred seventy-eight".