1987961822401 has 9 divisors (see below), whose sum is σ = 2058918385251. Its totient is φ = 1919371936104.

The previous prime is 1987961822347. The next prime is 1987961822477. The reversal of 1987961822401 is 1042281697891.

The square root of 1987961822401 is 1409951.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 1042438958001 + 945522864400 = 1020999^2 + 972380^2 .

It is a de Polignac number, because none of the positive numbers 2^k-1987961822401 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1987961822501) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 40864270 + ... + 40912888.

Almost surely, 2^{1987961822401} is an apocalyptic number.

1987961822401 is the 1409951-st square number.

1987961822401 is the 704976-th centered octagonal number.

It is an amenable number.

1987961822401 is a deficient number, since it is larger than the sum of its proper divisors (70956562850).

1987961822401 is an frugal number, since it uses more digits than its factorization.

1987961822401 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 97296 (or 48648 counting only the distinct ones).

The product of its (nonzero) digits is 3483648, while the sum is 58.

The spelling of 1987961822401 in words is "one trillion, nine hundred eighty-seven billion, nine hundred sixty-one million, eight hundred twenty-two thousand, four hundred one".