1621324540625 has 36 divisors (see below), whose sum is σ = 2074757886684. Its totient is φ = 1266890940000.

The previous prime is 1621324540579. The next prime is 1621324540637. The reversal of 1621324540625 is 5260454231261.

It can be written as a sum of positive squares in 6 ways, for example, as 1071067685776 + 550256854849 = 1034924^2 + 741793^2 .

It is not a de Polignac number, because 1621324540625 - 2⁴⁰ = 521812912849 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 5637827 + ... + 5918423.

It is an arithmetic number, because the mean of its divisors is an integer number (57632163519).

Almost surely, 2^{1621324540625} is an apocalyptic number.

It is an amenable number.

1621324540625 is a deficient number, since it is larger than the sum of its proper divisors (453433346059).

1621324540625 is an frugal number, since it uses more digits than its factorization.

1621324540625 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 280708 (or 280645 counting only the distinct ones).

The product of its (nonzero) digits is 345600, while the sum is 41.

Adding to 1621324540625 its reverse (5260454231261), we get a palindrome (6881778771886).

The spelling of 1621324540625 in words is "one trillion, six hundred twenty-one billion, three hundred twenty-four million, five hundred forty thousand, six hundred twenty-five".