10001221012 has 6 divisors (see below), whose sum is σ = 17502136778. Its totient is φ = 5000610504.

The previous prime is 10001221003. The next prime is 10001221019. The reversal of 10001221012 is 21012210001.

It can be written as a sum of positive squares in only one way, i.e., 9885529476 + 115691536 = 99426^2 + 10756^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 10001221012.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (10001221019) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1250152623 + ... + 1250152630.

Almost surely, 2^10001221012 is an apocalyptic number.

It is an amenable number.

10001221012 is a deficient number, since it is larger than the sum of its proper divisors (7500915766).

10001221012 is a wasteful number, since it uses less digits than its factorization.

10001221012 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2500305257 (or 2500305255 counting only the distinct ones).

The product of its (nonzero) digits is 8, while the sum is 10.

Adding to 10001221012 its reverse (21012210001), we get a palindrome (31013431013).

The spelling of 10001221012 in words is "ten billion, one million, two hundred twenty-one thousand, twelve".