21145543087 has 2 divisors, whose sum is σ = 21145543088. Its totient is φ = 21145543086.

The previous prime is 21145542961. The next prime is 21145543091. The reversal of 21145543087 is 78034554112.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21145543087 - 2³¹ = 18998059439 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21145543187) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10572771543 + 10572771544.

It is an arithmetic number, because the mean of its divisors is an integer number (10572771544).

Almost surely, 2^21145543087 is an apocalyptic number.

21145543087 is a deficient number, since it is larger than the sum of its proper divisors (1).

21145543087 is an equidigital number, since it uses as much as digits as its factorization.

21145543087 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 134400, while the sum is 40.

The spelling of 21145543087 in words is "twenty-one billion, one hundred forty-five million, five hundred forty-three thousand, eighty-seven".