21002012331973 has 2 divisors, whose sum is σ = 21002012331974. Its totient is φ = 21002012331972.

The previous prime is 21002012331943. The next prime is 21002012332013. The reversal of 21002012331973 is 37913321020012.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 14302782737604 + 6699229594369 = 3781902^2 + 2588287^2 .

It is a cyclic number.

It is not a de Polignac number, because 21002012331973 - 2⁵ = 21002012331941 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21002012331943) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10501006165986 + 10501006165987.

It is an arithmetic number, because the mean of its divisors is an integer number (10501006165987).

Almost surely, 2^{21002012331973} is an apocalyptic number.

It is an amenable number.

21002012331973 is a deficient number, since it is larger than the sum of its proper divisors (1).

21002012331973 is an equidigital number, since it uses as much as digits as its factorization.

21002012331973 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 13608, while the sum is 34.

Adding to 21002012331973 its reverse (37913321020012), we get a palindrome (58915333351985).

The spelling of 21002012331973 in words is "twenty-one trillion, two billion, twelve million, three hundred thirty-one thousand, nine hundred seventy-three".