616578561 has 45 divisors (see below), whose sum is σ = 962545683. Its totient is φ = 393323040.

The previous prime is 616578553. The next prime is 616578569. The reversal of 616578561 is 165875616.

The square root of 616578561 is 24831.

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

616578561 is a `hidden beast` number, since 6 + 16 + 5 + 78 + 561 = 666.

It is an interprime number because it is at equal distance from previous prime (616578553) and next prime (616578569).

It can be written as a sum of positive squares in only one way, i.e., 118396161 + 498182400 = 10881^2 + 22320^2 .

It is not a de Polignac number, because 616578561 - 2³ = 616578553 is a prime.

Its product of digits (302400) is a multiple of the sum of its prime factors (252).

It is not an unprimeable number, because it can be changed into a prime (616578569) by changing a digit.

It is a polite number, since it can be written in 44 ways as a sum of consecutive naturals, for example, 6927805 + ... + 6927893.

Almost surely, 2^616578561 is an apocalyptic number.

616578561 is the 24831-st square number.

616578561 is the 12416-th centered octagonal number.

It is an amenable number.

616578561 is a deficient number, since it is larger than the sum of its proper divisors (345967122).

616578561 is an frugal number, since it uses more digits than its factorization.

616578561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 252 (or 123 counting only the distinct ones).

The product of its digits is 302400, while the sum is 45.

The cubic root of 616578561 is about 851.1304732330.

The spelling of 616578561 in words is "six hundred sixteen million, five hundred seventy-eight thousand, five hundred sixty-one".