616331021 has 4 divisors (see below), whose sum is σ = 622091232. Its totient is φ = 610570812.

The previous prime is 616331003. The next prime is 616331029. The reversal of 616331021 is 120133616.

It is a happy number.

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 616331021 - 2¹⁸ = 616068877 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 (616331029) 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, 2879945 + ... + 2880158.

It is an arithmetic number, because the mean of its divisors is an integer number (155522808).

Almost surely, 2^616331021 is an apocalyptic number.

It is an amenable number.

616331021 is a deficient number, since it is larger than the sum of its proper divisors (5760211).

616331021 is a wasteful number, since it uses less digits than its factorization.

616331021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5760210.

The product of its (nonzero) digits is 648, while the sum is 23.

The square root of 616331021 is about 24826.0150044263. The cubic root of 616331021 is about 851.0165558550.

Adding to 616331021 its reverse (120133616), we get a palindrome (736464637).

The spelling of 616331021 in words is "six hundred sixteen million, three hundred thirty-one thousand, twenty-one".