21053678 has 16 divisors (see below), whose sum is σ = 32607360. Its totient is φ = 10190136.

The previous prime is 21053663. The next prime is 21053699. The reversal of 21053678 is 87635012.

It is a happy number.

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 6575 + ... + 9237.

It is an arithmetic number, because the mean of its divisors is an integer number (2037960).

Almost surely, 2^21053678 is an apocalyptic number.

21053678 is a deficient number, since it is larger than the sum of its proper divisors (11553682).

21053678 is a wasteful number, since it uses less digits than its factorization.

21053678 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2791.

The product of its (nonzero) digits is 10080, while the sum is 32.

The square root of 21053678 is about 4588.4287070848. The cubic root of 21053678 is about 276.1272867340.

The spelling of 21053678 in words is "twenty-one million, fifty-three thousand, six hundred seventy-eight".