21001402220 has 24 divisors (see below), whose sum is σ = 44295543600. Its totient is φ = 8363875392.

The previous prime is 21001402211. The next prime is 21001402249. The reversal of 21001402220 is 2220410012.

It is a junction number, because it is equal to n+sod(n) for n = 21001402195 and 21001402204.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2288150 + ... + 2297309.

It is an arithmetic number, because the mean of its divisors is an integer number (1845647650).

Almost surely, 2^21001402220 is an apocalyptic number.

21001402220 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21001402220 is an abundant number, since it is smaller than the sum of its proper divisors (23294141380).

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

21001402220 is a wasteful number, since it uses less digits than its factorization.

21001402220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4585697 (or 4585695 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 14.

Adding to 21001402220 its reverse (2220410012), we get a palindrome (23221812232).

The spelling of 21001402220 in words is "twenty-one billion, one million, four hundred two thousand, two hundred twenty".