21054678 has 8 divisors (see below), whose sum is σ = 42109368. Its totient is φ = 7018224.

The previous prime is 21054661. The next prime is 21054697. The reversal of 21054678 is 87645012.

It is a sphenic number, since it is the product of 3 distinct primes.

21054678 is an admirable number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1754551 + ... + 1754562.

It is an arithmetic number, because the mean of its divisors is an integer number (5263671).

Almost surely, 2^21054678 is an apocalyptic number.

21054678 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

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

21054678 is a wasteful number, since it uses less digits than its factorization.

21054678 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3509118.

The product of its (nonzero) digits is 13440, while the sum is 33.

The square root of 21054678 is about 4588.5376755563. The cubic root of 21054678 is about 276.1316584629.

The spelling of 21054678 in words is "twenty-one million, fifty-four thousand, six hundred seventy-eight".