21000031122320 has 40 divisors (see below), whose sum is σ = 48979094728824. Its totient is φ = 8373513976832.

The previous prime is 21000031122283. The next prime is 21000031122379. The reversal of 21000031122320 is 2322113000012.

It can be written as a sum of positive squares in 4 ways, for example, as 46927690384 + 20953103431936 = 216628^2 + 4577456^2 .

It is a tau number, because it is divible by the number of its divisors (40).

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, 414013109 + ... + 414063828.

Almost surely, 2^{21000031122320} is an apocalyptic number.

21000031122320 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21000031122320 is an abundant number, since it is smaller than the sum of its proper divisors (27979063606504).

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

21000031122320 is a wasteful number, since it uses less digits than its factorization.

21000031122320 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 828077267 (or 828077261 counting only the distinct ones).

The product of its (nonzero) digits is 144, while the sum is 17.

Adding to 21000031122320 its reverse (2322113000012), we get a palindrome (23322144122332).

The spelling of 21000031122320 in words is "twenty-one trillion, thirty-one million, one hundred twenty-two thousand, three hundred twenty".