21001000032 has 96 divisors (see below), whose sum is σ = 61280724960. Its totient is φ = 6997155840.

The previous prime is 21001000019. The next prime is 21001000037. The reversal of 21001000032 is 23000010012.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (96).

It is a Harshad number since it is a multiple of its sum of digits (9).

It is a junction number, because it is equal to n+sod(n) for n = 21000999978 and 21001000023.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21001000037) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2623428 + ... + 2631420.

It is an arithmetic number, because the mean of its divisors is an integer number (638340885).

Almost surely, 2^21001000032 is an apocalyptic number.

It is an amenable number.

21001000032 is an abundant number, since it is smaller than the sum of its proper divisors (40279724928).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21001000032 is a wasteful number, since it uses less digits than its factorization.

21001000032 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11053 (or 11039 counting only the distinct ones).

The product of its (nonzero) digits is 12, while the sum is 9.

Adding to 21001000032 its reverse (23000010012), we get a palindrome (44001010044).

The spelling of 21001000032 in words is "twenty-one billion, one million, thirty-two", and thus it is an aban number and an uban number.