21385554 has 8 divisors (see below), whose sum is σ = 42771120. Its totient is φ = 7128516.

The previous prime is 21385549. The next prime is 21385591. The reversal of 21385554 is 45558312.

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

21385554 is an admirable 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, 1782124 + ... + 1782135.

It is an arithmetic number, because the mean of its divisors is an integer number (5346390).

Almost surely, 2^21385554 is an apocalyptic number.

21385554 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.

21385554 is a wasteful number, since it uses less digits than its factorization.

21385554 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3564264.

The product of its digits is 24000, while the sum is 33.

The square root of 21385554 is about 4624.4517512890. The cubic root of 21385554 is about 277.5706240179.

The spelling of 21385554 in words is "twenty-one million, three hundred eighty-five thousand, five hundred fifty-four".