1616611621 has 2 divisors, whose sum is σ = 1616611622. Its totient is φ = 1616611620.

The previous prime is 1616611589. The next prime is 1616611627. The reversal of 1616611621 is 1261166161.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 882743521 + 733868100 = 29711^2 + 27090^2 .

It is a cyclic number.

It is not a de Polignac number, because 1616611621 - 2⁵ = 1616611589 is a prime.

It is a super-2 number, since 2×1616611621² = 5226866266304495282, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1616611627) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 808305810 + 808305811.

It is an arithmetic number, because the mean of its divisors is an integer number (808305811).

Almost surely, 2^1616611621 is an apocalyptic number.

It is an amenable number.

1616611621 is a deficient number, since it is larger than the sum of its proper divisors (1).

1616611621 is an equidigital number, since it uses as much as digits as its factorization.

1616611621 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2592, while the sum is 31.

The square root of 1616611621 is about 40207.1090853346. The cubic root of 1616611621 is about 1173.6408902256.

Adding to 1616611621 its reverse (1261166161), we get a palindrome (2877777782).

The spelling of 1616611621 in words is "one billion, six hundred sixteen million, six hundred eleven thousand, six hundred twenty-one".