616891281 has 4 divisors (see below), whose sum is σ = 822521712. Its totient is φ = 411260852.

The previous prime is 616891271. The next prime is 616891321. The reversal of 616891281 is 182198616.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 616891281 - 2⁶ = 616891217 is a prime.

It is a super-2 number, since 2×616891281² = 761109705147641922, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (616891241) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 102815211 + ... + 102815216.

It is an arithmetic number, because the mean of its divisors is an integer number (205630428).

Almost surely, 2^616891281 is an apocalyptic number.

It is an amenable number.

616891281 is a deficient number, since it is larger than the sum of its proper divisors (205630431).

616891281 is a wasteful number, since it uses less digits than its factorization.

616891281 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 205630430.

The product of its digits is 41472, while the sum is 42.

The square root of 616891281 is about 24837.2961692693. The cubic root of 616891281 is about 851.2743427265.

The spelling of 616891281 in words is "six hundred sixteen million, eight hundred ninety-one thousand, two hundred eighty-one".