21049953 has 8 divisors (see below), whose sum is σ = 28089600. Its totient is φ = 14021808.

The previous prime is 21049949. The next prime is 21050011. The reversal of 21049953 is 35994012.

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

It is not a de Polignac number, because 21049953 - 2² = 21049949 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21049153) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3283 + ... + 7271.

It is an arithmetic number, because the mean of its divisors is an integer number (3511200).

Almost surely, 2^21049953 is an apocalyptic number.

It is an amenable number.

21049953 is a deficient number, since it is larger than the sum of its proper divisors (7039647).

21049953 is a wasteful number, since it uses less digits than its factorization.

21049953 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5751.

The product of its (nonzero) digits is 9720, while the sum is 33.

The square root of 21049953 is about 4588.0227767525. The cubic root of 21049953 is about 276.1110008257. Note that the first 3 decimals are identical.

The spelling of 21049953 in words is "twenty-one million, forty-nine thousand, nine hundred fifty-three".