1216553850625 has 15 divisors (see below), whose sum is σ = 1520240149461. Its totient is φ = 973221021000.

The previous prime is 1216553850619. The next prime is 1216553850641. The reversal of 1216553850625 is 5260583556121.

The square root of 1216553850625 is 1102975.

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

It can be written as a sum of positive squares in 2 ways, for example, as 95377821889 + 1121176028736 = 308833^2 + 1058856^2 .

It is not a de Polignac number, because 1216553850625 - 2⁷ = 1216553850497 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 14 ways as a sum of consecutive naturals, for example, 27552316 + ... + 27596434.

Almost surely, 2^{1216553850625} is an apocalyptic number.

1216553850625 is the 1102975-th square number.

1216553850625 is the 551488-th centered octagonal number.

It is an amenable number.

1216553850625 is a deficient number, since it is larger than the sum of its proper divisors (303686298836).

1216553850625 is an frugal number, since it uses more digits than its factorization.

1216553850625 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 88258 (or 44124 counting only the distinct ones).

The product of its (nonzero) digits is 2160000, while the sum is 49.

Multiplying 1216553850625 by its sum of digits (49), we get a square (59611138680625 = 7720825²).

The spelling of 1216553850625 in words is "one trillion, two hundred sixteen billion, five hundred fifty-three million, eight hundred fifty thousand, six hundred twenty-five".