21001323849 has 32 divisors (see below), whose sum is σ = 31643360640. Its totient is φ = 12272601600.

The previous prime is 21001323841. The next prime is 21001323853. The reversal of 21001323849 is 94832310012.

It is not a de Polignac number, because 21001323849 - 2³ = 21001323841 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (33).

It is not an unprimeable number, because it can be changed into a prime (21001323841) 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 31 ways as a sum of consecutive naturals, for example, 713859 + ... + 742695.

It is an arithmetic number, because the mean of its divisors is an integer number (988855020).

Almost surely, 2^21001323849 is an apocalyptic number.

21001323849 is a gapful number since it is divisible by the number (29) formed by its first and last digit.

It is an amenable number.

21001323849 is a deficient number, since it is larger than the sum of its proper divisors (10642036791).

21001323849 is a wasteful number, since it uses less digits than its factorization.

21001323849 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 29641.

The product of its (nonzero) digits is 10368, while the sum is 33.

The spelling of 21001323849 in words is "twenty-one billion, one million, three hundred twenty-three thousand, eight hundred forty-nine".