1620104116521 has 16 divisors (see below), whose sum is σ = 2356539768000. Its totient is φ = 981870995520.

The previous prime is 1620104116487. The next prime is 1620104116537. The reversal of 1620104116521 is 1256114010261.

It is not a de Polignac number, because 1620104116521 - 2²¹ = 1620102019369 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (1620104516521) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3984355 + ... + 4372103.

It is an arithmetic number, because the mean of its divisors is an integer number (147283735500).

Almost surely, 2^{1620104116521} is an apocalyptic number.

1620104116521 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

1620104116521 is a deficient number, since it is larger than the sum of its proper divisors (736435651479).

1620104116521 is a wasteful number, since it uses less digits than its factorization.

1620104116521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 514376.

The product of its (nonzero) digits is 2880, while the sum is 30.

Adding to 1620104116521 its reverse (1256114010261), we get a palindrome (2876218126782).

The spelling of 1620104116521 in words is "one trillion, six hundred twenty billion, one hundred four million, one hundred sixteen thousand, five hundred twenty-one".