616772781 has 12 divisors (see below), whose sum is σ = 891259200. Its totient is φ = 411013320.

The previous prime is 616772771. The next prime is 616772791. The reversal of 616772781 is 187277616.

616772781 is a `hidden beast` number, since 616 + 7 + 7 + 27 + 8 + 1 = 666.

It is an interprime number because it is at equal distance from previous prime (616772771) and next prime (616772791).

It is not a de Polignac number, because 616772781 - 2⁵ = 616772749 is a prime.

It is a super-2 number, since 2×616772781² = 760817326764947922, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (616772771) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 11596 + ... + 36986.

It is an arithmetic number, because the mean of its divisors is an integer number (74271600).

Almost surely, 2^616772781 is an apocalyptic number.

It is an amenable number.

616772781 is a deficient number, since it is larger than the sum of its proper divisors (274486419).

616772781 is a wasteful number, since it uses less digits than its factorization.

616772781 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 28096 (or 28093 counting only the distinct ones).

The product of its digits is 197568, while the sum is 45.

The square root of 616772781 is about 24834.9105293335. The cubic root of 616772781 is about 851.2198315170.

The spelling of 616772781 in words is "six hundred sixteen million, seven hundred seventy-two thousand, seven hundred eighty-one".