36561534421621 has 12 divisors (see below), whose sum is σ = 40330487670732. Its totient is φ = 33119474696000.

The previous prime is 36561534421589. The next prime is 36561534421651. The reversal of 36561534421621 is 12612443516563.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 17999103226225 + 18562431195396 = 4242535^2 + 4308414^2 .

It is not a de Polignac number, because 36561534421621 - 2⁵ = 36561534421589 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 (36561534421651) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 537619810 + ... + 537687811.

It is an arithmetic number, because the mean of its divisors is an integer number (3360873972561).

Almost surely, 2^{36561534421621} is an apocalyptic number.

It is an amenable number.

36561534421621 is a deficient number, since it is larger than the sum of its proper divisors (3768953249111).

36561534421621 is a wasteful number, since it uses less digits than its factorization.

36561534421621 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1075307924 (or 1075307913 counting only the distinct ones).

The product of its digits is 3110400, while the sum is 49.

The spelling of 36561534421621 in words is "thirty-six trillion, five hundred sixty-one billion, five hundred thirty-four million, four hundred twenty-one thousand, six hundred twenty-one".