1201002021 has 6 divisors (see below), whose sum is σ = 1734780710. Its totient is φ = 800668008.

The previous prime is 1201002013. The next prime is 1201002071. The reversal of 1201002021 is 1202001021.

It can be written as a sum of positive squares in only one way, i.e., 1198128996 + 2873025 = 34614^2 + 1695^2 .

It is not a de Polignac number, because 1201002021 - 2³ = 1201002013 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (9), and also a Moran number because the ratio is a prime number: 133444669 = 1201002021 / (1 + 2 + 0 + 1 + 0 + 0 + 2 + 0 + 2 + 1).

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1201001994 and 1201002012.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1201002071) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 66722326 + ... + 66722343.

Almost surely, 2^1201002021 is an apocalyptic number.

It is an amenable number.

1201002021 is a deficient number, since it is larger than the sum of its proper divisors (533778689).

1201002021 is a wasteful number, since it uses less digits than its factorization.

1201002021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 133444675 (or 133444672 counting only the distinct ones).

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

The square root of 1201002021 is about 34655.4760607902. The cubic root of 1201002021 is about 1062.9542663944.

Adding to 1201002021 its reverse (1202001021), we get a palindrome (2403003042).

The spelling of 1201002021 in words is "one billion, two hundred one million, two thousand, twenty-one".