21131220311989 has 8 divisors (see below), whose sum is σ = 21340548754848. Its totient is φ = 20921893995600.

The previous prime is 21131220311953. The next prime is 21131220312023. The reversal of 21131220311989 is 98911302213112.

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

It is a cyclic number.

It is not a de Polignac number, because 21131220311989 - 2⁹ = 21131220311477 is a prime.

It is a super-2 number, since 2×21131220311989² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21131220311189) 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, 25934254 + ... + 26736640.

It is an arithmetic number, because the mean of its divisors is an integer number (2667568594356).

Almost surely, 2^{21131220311989} is an apocalyptic number.

It is an amenable number.

21131220311989 is a deficient number, since it is larger than the sum of its proper divisors (209328442859).

21131220311989 is a wasteful number, since it uses less digits than its factorization.

21131220311989 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1063235.

The product of its (nonzero) digits is 46656, while the sum is 43.

The spelling of 21131220311989 in words is "twenty-one trillion, one hundred thirty-one billion, two hundred twenty million, three hundred eleven thousand, nine hundred eighty-nine".