1997521512850 has 24 divisors (see below), whose sum is σ = 3740325531300. Its totient is φ = 793646128320.

The previous prime is 1997521512829. The next prime is 1997521512881. The reversal of 1997521512850 is 582151257991.

It can be written as a sum of positive squares in 6 ways, for example, as 568466237089 + 1429055275761 = 753967^2 + 1195431^2 .

It is a junction number, because it is equal to n+sod(n) for n = 1997521512791 and 1997521512800.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 134054397 + ... + 134069296.

Almost surely, 2^{1997521512850} is an apocalyptic number.

1997521512850 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

1997521512850 is a deficient number, since it is larger than the sum of its proper divisors (1742804018450).

1997521512850 is a wasteful number, since it uses less digits than its factorization.

1997521512850 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 268123854 (or 268123849 counting only the distinct ones).

The product of its (nonzero) digits is 2268000, while the sum is 55.

The spelling of 1997521512850 in words is "one trillion, nine hundred ninety-seven billion, five hundred twenty-one million, five hundred twelve thousand, eight hundred fifty".