21514732651021 has 2 divisors, whose sum is σ = 21514732651022. Its totient is φ = 21514732651020.

The previous prime is 21514732651019. The next prime is 21514732651033. The reversal of 21514732651021 is 12015623741512.

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., 15200875368900 + 6313857282121 = 3898830^2 + 2512739^2 .

It is a cyclic number.

It is not a de Polignac number, because 21514732651021 - 2¹ = 21514732651019 is a prime.

Together with 21514732651019, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21514732651091) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10757366325510 + 10757366325511.

It is an arithmetic number, because the mean of its divisors is an integer number (10757366325511).

Almost surely, 2^{21514732651021} is an apocalyptic number.

It is an amenable number.

21514732651021 is a deficient number, since it is larger than the sum of its proper divisors (1).

21514732651021 is an equidigital number, since it uses as much as digits as its factorization.

21514732651021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 100800, while the sum is 40.

The spelling of 21514732651021 in words is "twenty-one trillion, five hundred fourteen billion, seven hundred thirty-two million, six hundred fifty-one thousand, twenty-one".