1200001002021 has 48 divisors (see below), whose sum is σ = 1786136654016. Its totient is φ = 775904064768.

The previous prime is 1200001001999. The next prime is 1200001002059. The reversal of 1200001002021 is 1202001000021.

It is not a de Polignac number, because 1200001002021 - 2⁵ = 1200001001989 is a prime.

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 = 1200001001994 and 1200001002012.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1200001002061) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 55357641 + ... + 55379313.

It is an arithmetic number, because the mean of its divisors is an integer number (37211180292).

Almost surely, 2^{1200001002021} is an apocalyptic number.

It is an amenable number.

1200001002021 is a deficient number, since it is larger than the sum of its proper divisors (586135651995).

1200001002021 is a wasteful number, since it uses less digits than its factorization.

1200001002021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22722 (or 22719 counting only the distinct ones).

The product of its (nonzero) digits is 8, while the sum is 9.

Adding to 1200001002021 its reverse (1202001000021), we get a palindrome (2402002002042).

The spelling of 1200001002021 in words is "one trillion, two hundred billion, one million, two thousand, twenty-one".