21113211021 has 8 divisors (see below), whose sum is σ = 32172512064. Its totient is φ = 12064692000.

The previous prime is 21113211017. The next prime is 21113211023. The reversal of 21113211021 is 12011231112.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 21113211021 - 2² = 21113211017 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21113211023) 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, 502695480 + ... + 502695521.

It is an arithmetic number, because the mean of its divisors is an integer number (4021564008).

Almost surely, 2^21113211021 is an apocalyptic number.

21113211021 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

21113211021 is a deficient number, since it is larger than the sum of its proper divisors (11059301043).

21113211021 is a wasteful number, since it uses less digits than its factorization.

21113211021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1005391011.

The product of its (nonzero) digits is 24, while the sum is 15.

Adding to 21113211021 its reverse (12011231112), we get a palindrome (33124442133).

The spelling of 21113211021 in words is "twenty-one billion, one hundred thirteen million, two hundred eleven thousand, twenty-one".