21154533213529 has 2 divisors, whose sum is σ = 21154533213530. Its totient is φ = 21154533213528.

The previous prime is 21154533213433. The next prime is 21154533213547. The reversal of 21154533213529 is 92531233545112.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 18860580637129 + 2293952576400 = 4342877^2 + 1514580^2 .

It is a cyclic number.

It is not a de Polignac number, because 21154533213529 - 2²¹ = 21154531116377 is a prime.

It is not a weakly prime, because it can be changed into another prime (21154533213629) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10577266606764 + 10577266606765.

It is an arithmetic number, because the mean of its divisors is an integer number (10577266606765).

Almost surely, 2^{21154533213529} is an apocalyptic number.

It is an amenable number.

21154533213529 is a deficient number, since it is larger than the sum of its proper divisors (1).

21154533213529 is an equidigital number, since it uses as much as digits as its factorization.

21154533213529 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 972000, while the sum is 46.

The spelling of 21154533213529 in words is "twenty-one trillion, one hundred fifty-four billion, five hundred thirty-three million, two hundred thirteen thousand, five hundred twenty-nine".