3216421565 has 16 divisors (see below), whose sum is σ = 4419038592. Its totient is φ = 2201573184.

The previous prime is 3216421553. The next prime is 3216421577. The reversal of 3216421565 is 5651246123.

It is an interprime number because it is at equal distance from previous prime (3216421553) and next prime (3216421577).

It is a cyclic number.

It is not a de Polignac number, because 3216421565 - 2²⁸ = 2947986109 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (35).

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 62999 + ... + 101988.

It is an arithmetic number, because the mean of its divisors is an integer number (276189912).

Almost surely, 2^3216421565 is an apocalyptic number.

3216421565 is a gapful number since it is divisible by the number (35) formed by its first and last digit.

It is an amenable number.

3216421565 is a deficient number, since it is larger than the sum of its proper divisors (1202617027).

3216421565 is a wasteful number, since it uses less digits than its factorization.

3216421565 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 165556.

The product of its digits is 43200, while the sum is 35.

The square root of 3216421565 is about 56713.5042560412. The cubic root of 3216421565 is about 1476.1290315747.

Adding to 3216421565 its reverse (5651246123), we get a palindrome (8867667688).

The spelling of 3216421565 in words is "three billion, two hundred sixteen million, four hundred twenty-one thousand, five hundred sixty-five".