21221049 has 16 divisors (see below), whose sum is σ = 30101760. Its totient is φ = 13251840.

The previous prime is 21221047. The next prime is 21221051. The reversal of 21221049 is 94012212.

It is an interprime number because it is at equal distance from previous prime (21221047) and next prime (21221051).

It is not a de Polignac number, because 21221049 - 2¹ = 21221047 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21221047) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 11319 + ... + 13059.

It is an arithmetic number, because the mean of its divisors is an integer number (1881360).

Almost surely, 2^21221049 is an apocalyptic number.

It is an amenable number.

21221049 is a deficient number, since it is larger than the sum of its proper divisors (8880711).

21221049 is a wasteful number, since it uses less digits than its factorization.

21221049 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2000.

The product of its (nonzero) digits is 288, while the sum is 21.

The square root of 21221049 is about 4606.6309815309. The cubic root of 21221049 is about 276.8570684968.

The spelling of 21221049 in words is "twenty-one million, two hundred twenty-one thousand, forty-nine".