21202015973 has 2 divisors, whose sum is σ = 21202015974. Its totient is φ = 21202015972.

The previous prime is 21202015949. The next prime is 21202015993. The reversal of 21202015973 is 37951020212.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 15158041924 + 6043974049 = 123118^2 + 77743^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21202015973 is a prime.

It is a super-3 number, since 3×21202015973³ (a number of 32 digits) contains 333 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21202015903) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10601007986 + 10601007987.

It is an arithmetic number, because the mean of its divisors is an integer number (10601007987).

Almost surely, 2^21202015973 is an apocalyptic number.

It is an amenable number.

21202015973 is a deficient number, since it is larger than the sum of its proper divisors (1).

21202015973 is an equidigital number, since it uses as much as digits as its factorization.

21202015973 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 7560, while the sum is 32.

The spelling of 21202015973 in words is "twenty-one billion, two hundred two million, fifteen thousand, nine hundred seventy-three".