1200021999961 has 2 divisors, whose sum is σ = 1200021999962. Its totient is φ = 1200021999960.

The previous prime is 1200021999941. The next prime is 1200022000031. The reversal of 1200021999961 is 1699991200021.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1189122639961 + 10899360000 = 1090469^2 + 104400^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1200021999961 is a prime.

It is not a weakly prime, because it can be changed into another prime (1200021999941) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 600010999980 + 600010999981.

It is an arithmetic number, because the mean of its divisors is an integer number (600010999981).

Almost surely, 2^{1200021999961} is an apocalyptic number.

It is an amenable number.

1200021999961 is a deficient number, since it is larger than the sum of its proper divisors (1).

1200021999961 is an equidigital number, since it uses as much as digits as its factorization.

1200021999961 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 157464, while the sum is 49.

The spelling of 1200021999961 in words is "one trillion, two hundred billion, twenty-one million, nine hundred ninety-nine thousand, nine hundred sixty-one".