21221200401 has 32 divisors (see below), whose sum is σ = 29939632128. Its totient is φ = 13343721600.

The previous prime is 21221200397. The next prime is 21221200411. The reversal of 21221200401 is 10400212212.

It is not a de Polignac number, because 21221200401 - 2² = 21221200397 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21221200411) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1419970 + ... + 1434836.

It is an arithmetic number, because the mean of its divisors is an integer number (935613504).

Almost surely, 2^21221200401 is an apocalyptic number.

It is an amenable number.

21221200401 is a deficient number, since it is larger than the sum of its proper divisors (8718431727).

21221200401 is a wasteful number, since it uses less digits than its factorization.

21221200401 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15181.

The product of its (nonzero) digits is 64, while the sum is 15.

Adding to 21221200401 its reverse (10400212212), we get a palindrome (31621412613).

The spelling of 21221200401 in words is "twenty-one billion, two hundred twenty-one million, two hundred thousand, four hundred one".