1250011205521 has 27 divisors (see below), whose sum is σ = 1438151631921. Its totient is φ = 1085767922304.

The previous prime is 1250011205519. The next prime is 1250011205533. The reversal of 1250011205521 is 1255021100521.

It is a happy number.

The square root of 1250011205521 is 1118039.

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

It can be written as a sum of positive squares in 4 ways, for example, as 11286725121 + 1238724480400 = 106239^2 + 1112980^2 .

It is not a de Polignac number, because 1250011205521 - 2¹ = 1250011205519 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1250011205561) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 247084090 + ... + 247089148.

Almost surely, 2^{1250011205521} is an apocalyptic number.

1250011205521 is the 1118039-th square number.

1250011205521 is the 559020-th centered octagonal number.

It is an amenable number.

1250011205521 is a deficient number, since it is larger than the sum of its proper divisors (188140426400).

1250011205521 is an frugal number, since it uses more digits than its factorization.

1250011205521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10178 (or 5089 counting only the distinct ones).

The product of its (nonzero) digits is 1000, while the sum is 25.

Multiplying 1250011205521 by its sum of digits (25), we get a square (31250280138025 = 5590195²).

The spelling of 1250011205521 in words is "one trillion, two hundred fifty billion, eleven million, two hundred five thousand, five hundred twenty-one".