21224005406 has 16 divisors (see below), whose sum is σ = 31903877760. Its totient is φ = 10589405400.

The previous prime is 21224005391. The next prime is 21224005409. The reversal of 21224005406 is 60450042212.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21224005409) 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, 1926245 + ... + 1937231.

It is an arithmetic number, because the mean of its divisors is an integer number (1993992360).

Almost surely, 2^21224005406 is an apocalyptic number.

21224005406 is a deficient number, since it is larger than the sum of its proper divisors (10679872354).

21224005406 is a wasteful number, since it uses less digits than its factorization.

21224005406 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12959.

The product of its (nonzero) digits is 3840, while the sum is 26.

Adding to 21224005406 its reverse (60450042212), we get a palindrome (81674047618).

The spelling of 21224005406 in words is "twenty-one billion, two hundred twenty-four million, five thousand, four hundred six".