21949311 has 16 divisors (see below), whose sum is σ = 29723904. Its totient is φ = 14406144.

The previous prime is 21949303. The next prime is 21949331. The reversal of 21949311 is 11394912.

It is not a de Polignac number, because 21949311 - 2³ = 21949303 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21949331) 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, 96580 + ... + 96806.

It is an arithmetic number, because the mean of its divisors is an integer number (1857744).

Almost surely, 2^21949311 is an apocalyptic number.

21949311 is a deficient number, since it is larger than the sum of its proper divisors (7774593).

21949311 is a wasteful number, since it uses less digits than its factorization.

21949311 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 590.

The product of its digits is 1944, while the sum is 30.

The square root of 21949311 is about 4685.0091782194. The cubic root of 21949311 is about 279.9885667100.

The spelling of 21949311 in words is "twenty-one million, nine hundred forty-nine thousand, three hundred eleven".