1980242798521 has 9 divisors (see below), whose sum is σ = 2144306390031. Its totient is φ = 1827899542872.

The previous prime is 1980242798503. The next prime is 1980242798531. The reversal of 1980242798521 is 1258972420891.

The square root of 1980242798521 is 1407211.

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., 292935325225 + 1687307473296 = 541235^2 + 1298964^2 .

It is not a de Polignac number, because 1980242798521 - 2⁷ = 1980242798393 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1980242798531) 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, 18239620 + ... + 18347866.

It is an arithmetic number, because the mean of its divisors is an integer number (238256265559).

Almost surely, 2^{1980242798521} is an apocalyptic number.

1980242798521 is the 1407211-st square number.

1980242798521 is the 703606-th centered octagonal number.

It is an amenable number.

1980242798521 is a deficient number, since it is larger than the sum of its proper divisors (164063591510).

1980242798521 is an frugal number, since it uses more digits than its factorization.

1980242798521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 216520 (or 108260 counting only the distinct ones).

The product of its (nonzero) digits is 5806080, while the sum is 58.

The spelling of 1980242798521 in words is "one trillion, nine hundred eighty billion, two hundred forty-two million, seven hundred ninety-eight thousand, five hundred twenty-one".