616554721 has 8 divisors (see below), whose sum is σ = 643878144. Its totient is φ = 589274400.

The previous prime is 616554613. The next prime is 616554739. The reversal of 616554721 is 127455616.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 616554721 - 2¹⁹ = 616030433 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (616554751) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 20421 + ... + 40621.

It is an arithmetic number, because the mean of its divisors is an integer number (80484768).

Almost surely, 2^616554721 is an apocalyptic number.

It is an amenable number.

616554721 is a deficient number, since it is larger than the sum of its proper divisors (27323423).

616554721 is a wasteful number, since it uses less digits than its factorization.

616554721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21551.

The product of its digits is 50400, while the sum is 37.

The square root of 616554721 is about 24830.5199502548. The cubic root of 616554721 is about 851.1195034430.

The spelling of 616554721 in words is "six hundred sixteen million, five hundred fifty-four thousand, seven hundred twenty-one".