21221431404 has 24 divisors (see below), whose sum is σ = 49598266368. Its totient is φ = 7062154320.

The previous prime is 21221431369. The next prime is 21221431433. The reversal of 21221431404 is 40413412212.

It is a super-2 number, since 2×21221431404² (a number of 21 digits) contains 22 as substring.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1449432 + ... + 1463999.

It is an arithmetic number, because the mean of its divisors is an integer number (2066594432).

Almost surely, 2^21221431404 is an apocalyptic number.

It is an amenable number.

21221431404 is an abundant number, since it is smaller than the sum of its proper divisors (28376834964).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21221431404 is a wasteful number, since it uses less digits than its factorization.

21221431404 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2914045 (or 2914043 counting only the distinct ones).

The product of its (nonzero) digits is 1536, while the sum is 24.

Adding to 21221431404 its reverse (40413412212), we get a palindrome (61634843616).

The spelling of 21221431404 in words is "twenty-one billion, two hundred twenty-one million, four hundred thirty-one thousand, four hundred four".