21326057571 has 64 divisors (see below), whose sum is σ = 36190945280. Its totient is φ = 10866337920.

The previous prime is 21326057569. The next prime is 21326057573. The reversal of 21326057571 is 17575062312.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (21326057569) and next prime (21326057573).

It is not a de Polignac number, because 21326057571 - 2¹ = 21326057569 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (39).

It is not an unprimeable number, because it can be changed into a prime (21326057573) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 5439750 + ... + 5443668.

It is an arithmetic number, because the mean of its divisors is an integer number (565483520).

Almost surely, 2^21326057571 is an apocalyptic number.

21326057571 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

21326057571 is a deficient number, since it is larger than the sum of its proper divisors (14864887709).

21326057571 is a wasteful number, since it uses less digits than its factorization.

21326057571 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4616.

The product of its (nonzero) digits is 88200, while the sum is 39.

The spelling of 21326057571 in words is "twenty-one billion, three hundred twenty-six million, fifty-seven thousand, five hundred seventy-one".