21950811 has 16 divisors (see below), whose sum is σ = 32599200. Its totient is φ = 14598144.

The previous prime is 21950801. The next prime is 21950827. The reversal of 21950811 is 11805912.

It is not a de Polignac number, because 21950811 - 2⁵ = 21950779 is a prime.

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

It is not an unprimeable number, because it can be changed into a prime (21950801) 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, 14875 + ... + 16283.

It is an arithmetic number, because the mean of its divisors is an integer number (2037450).

Almost surely, 2^21950811 is an apocalyptic number.

21950811 is a deficient number, since it is larger than the sum of its proper divisors (10648389).

21950811 is a wasteful number, since it uses less digits than its factorization.

21950811 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1995 (or 1989 counting only the distinct ones).

The product of its (nonzero) digits is 720, while the sum is 27.

The square root of 21950811 is about 4685.1692605497. The cubic root of 21950811 is about 279.9949446366.

The spelling of 21950811 in words is "twenty-one million, nine hundred fifty thousand, eight hundred eleven".