20015247250021 has 2 divisors, whose sum is σ = 20015247250022. Its totient is φ = 20015247250020.

The previous prime is 20015247249973. The next prime is 20015247250079. The reversal of 20015247250021 is 12005274251002.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 17435092536225 + 2580154713796 = 4175535^2 + 1606286^2 .

It is a cyclic number.

It is not a de Polignac number, because 20015247250021 - 2¹⁵ = 20015247217253 is a prime.

It is a super-2 number, since 2×20015247250021² (a number of 27 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20015247250091) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10007623625010 + 10007623625011.

It is an arithmetic number, because the mean of its divisors is an integer number (10007623625011).

Almost surely, 2^{20015247250021} is an apocalyptic number.

It is an amenable number.

20015247250021 is a deficient number, since it is larger than the sum of its proper divisors (1).

20015247250021 is an equidigital number, since it uses as much as digits as its factorization.

20015247250021 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 11200, while the sum is 31.

The spelling of 20015247250021 in words is "twenty trillion, fifteen billion, two hundred forty-seven million, two hundred fifty thousand, twenty-one".