21001200993 has 16 divisors (see below), whose sum is σ = 31115128000. Its totient is φ = 13999793760.

The previous prime is 21001200991. The next prime is 21001201127. The reversal of 21001200993 is 39900210012.

It is not a de Polignac number, because 21001200993 - 2¹ = 21001200991 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21001200991) 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 15 ways as a sum of consecutive naturals, for example, 682878 + ... + 712968.

It is an arithmetic number, because the mean of its divisors is an integer number (1944695500).

Almost surely, 2^21001200993 is an apocalyptic number.

It is an amenable number.

21001200993 is a deficient number, since it is larger than the sum of its proper divisors (10113927007).

21001200993 is a wasteful number, since it uses less digits than its factorization.

21001200993 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 55949 (or 55943 counting only the distinct ones).

The product of its (nonzero) digits is 972, while the sum is 27.

The spelling of 21001200993 in words is "twenty-one billion, one million, two hundred thousand, nine hundred ninety-three".