21001331012 has 24 divisors (see below), whose sum is σ = 38029483800. Its totient is φ = 10135951616.

The previous prime is 21001330969. The next prime is 21001331033. The reversal of 21001331012 is 21013310012.

It can be written as a sum of positive squares in 4 ways, for example, as 430313536 + 20571017476 = 20744^2 + 143426^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 472064 + ... + 514632.

It is an arithmetic number, because the mean of its divisors is an integer number (1584561825).

Almost surely, 2^21001331012 is an apocalyptic number.

It is an amenable number.

21001331012 is a deficient number, since it is larger than the sum of its proper divisors (17028152788).

21001331012 is a wasteful number, since it uses less digits than its factorization.

21001331012 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 46855 (or 46853 counting only the distinct ones).

The product of its (nonzero) digits is 36, while the sum is 14.

Adding to 21001331012 its reverse (21013310012), we get a palindrome (42014641024).

The spelling of 21001331012 in words is "twenty-one billion, one million, three hundred thirty-one thousand, twelve".