21955546 has 4 divisors (see below), whose sum is σ = 32933322. Its totient is φ = 10977772.

The previous prime is 21955463. The next prime is 21955559. The reversal of 21955546 is 64555912.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 17732521 + 4223025 = 4211^2 + 2055^2 .

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5488885 + ... + 5488888.

Almost surely, 2^21955546 is an apocalyptic number.

21955546 is a deficient number, since it is larger than the sum of its proper divisors (10977776).

21955546 is a wasteful number, since it uses less digits than its factorization.

21955546 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10977775.

The product of its digits is 54000, while the sum is 37.

The square root of 21955546 is about 4685.6745512253. The cubic root of 21955546 is about 280.0150757189.

It can be divided in two parts, 2195554 and 6, that added together give a triangular number (2195560 = T₂₀₉₅).

The spelling of 21955546 in words is "twenty-one million, nine hundred fifty-five thousand, five hundred forty-six".