2001221212402 has 4 divisors (see below), whose sum is σ = 3001831818606. Its totient is φ = 1000610606200.

The previous prime is 2001221212391. The next prime is 2001221212513. The reversal of 2001221212402 is 2042121221002.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 1957819406841 + 43401805561 = 1399221^2 + 208331^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 2001221212402.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 500305303099 + ... + 500305303102.

Almost surely, 2^{2001221212402} is an apocalyptic number.

2001221212402 is a deficient number, since it is larger than the sum of its proper divisors (1000610606204).

2001221212402 is a wasteful number, since it uses less digits than its factorization.

2001221212402 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1000610606203.

The product of its (nonzero) digits is 256, while the sum is 19.

Adding to 2001221212402 its reverse (2042121221002), we get a palindrome (4043342433404).

The spelling of 2001221212402 in words is "two trillion, one billion, two hundred twenty-one million, two hundred twelve thousand, four hundred two".