21046554 has 20 divisors (see below), whose sum is σ = 47160234. Its totient is φ = 7015464.

The previous prime is 21046549. The next prime is 21046573. The reversal of 21046554 is 45564012.

21046554 is a `hidden beast` number, since 2 + 1 + 0 + 4 + 655 + 4 = 666.

It can be written as a sum of positive squares in only one way, i.e., 16184529 + 4862025 = 4023^2 + 2205^2 .

It is a Harshad number since it is a multiple of its sum of digits (27).

It is an unprimeable number.

It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 64797 + ... + 65120.

Almost surely, 2^21046554 is an apocalyptic number.

21046554 is an abundant number, since it is smaller than the sum of its proper divisors (26113680).

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

21046554 is a wasteful number, since it uses less digits than its factorization.

21046554 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 129931 (or 129922 counting only the distinct ones).

The product of its (nonzero) digits is 4800, while the sum is 27.

The square root of 21046554 is about 4587.6523407948. The cubic root of 21046554 is about 276.0961385311.

It can be divided in two parts, 210 and 46554, that added together give a palindrome (46764).

The spelling of 21046554 in words is "twenty-one million, forty-six thousand, five hundred fifty-four".