2121640232564 has 12 divisors (see below), whose sum is σ = 3712883828388. Its totient is φ = 1060816281600.

The previous prime is 2121640232563. The next prime is 2121640232599. The reversal of 2121640232564 is 4652320461212.

It can be written as a sum of positive squares in 2 ways, for example, as 1822748408464 + 298891824100 = 1350092^2 + 546710^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2121640232563) 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, 550004 + ... + 2132084.

It is an arithmetic number, because the mean of its divisors is an integer number (309406985699).

Almost surely, 2^{2121640232564} is an apocalyptic number.

It is an amenable number.

2121640232564 is a deficient number, since it is larger than the sum of its proper divisors (1591243595824).

2121640232564 is a wasteful number, since it uses less digits than its factorization.

2121640232564 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1917346 (or 1917344 counting only the distinct ones).

The product of its (nonzero) digits is 138240, while the sum is 38.

Adding to 2121640232564 its reverse (4652320461212), we get a palindrome (6773960693776).

The spelling of 2121640232564 in words is "two trillion, one hundred twenty-one billion, six hundred forty million, two hundred thirty-two thousand, five hundred sixty-four".