616521653 has 4 divisors (see below), whose sum is σ = 672569088. Its totient is φ = 560474220.

The previous prime is 616521637. The next prime is 616521667. The reversal of 616521653 is 356125616.

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 616521653 - 2⁴ = 616521637 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (616521623) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 28023701 + ... + 28023722.

It is an arithmetic number, because the mean of its divisors is an integer number (168142272).

Almost surely, 2^616521653 is an apocalyptic number.

It is an amenable number.

616521653 is a deficient number, since it is larger than the sum of its proper divisors (56047435).

616521653 is a wasteful number, since it uses less digits than its factorization.

616521653 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 56047434.

The product of its digits is 32400, while the sum is 35.

The square root of 616521653 is about 24829.8540672312. The cubic root of 616521653 is about 851.1042869926.

The spelling of 616521653 in words is "six hundred sixteen million, five hundred twenty-one thousand, six hundred fifty-three".