221561262499 has 4 divisors (see below), whose sum is σ = 221562756360. Its totient is φ = 221559768640.

The previous prime is 221561262493. The next prime is 221561262521. The reversal of 221561262499 is 994262165122.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 221561262499 - 2⁵ = 221561262467 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (221561262493) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 496462 + ... + 830419.

It is an arithmetic number, because the mean of its divisors is an integer number (55390689090).

Almost surely, 2^221561262499 is an apocalyptic number.

221561262499 is a deficient number, since it is larger than the sum of its proper divisors (1493861).

221561262499 is a wasteful number, since it uses less digits than its factorization.

221561262499 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1493860.

The product of its digits is 933120, while the sum is 49.

The spelling of 221561262499 in words is "two hundred twenty-one billion, five hundred sixty-one million, two hundred sixty-two thousand, four hundred ninety-nine".