20616405121 has 8 divisors (see below), whose sum is σ = 23508299304. Its totient is φ = 17911084800.

The previous prime is 20616405071. The next prime is 20616405149. The reversal of 20616405121 is 12150461602.

It can be written as a sum of positive squares in 4 ways, for example, as 1479556225 + 19136848896 = 38465^2 + 138336^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 20616405121 - 2⁹ = 20616404609 is a prime.

It is a super-2 number, since 2×20616405121² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 20616405121.

It is not an unprimeable number, because it can be changed into a prime (20616405151) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 46643230 + ... + 46643671.

It is an arithmetic number, because the mean of its divisors is an integer number (2938537413).

Almost surely, 2^20616405121 is an apocalyptic number.

It is an amenable number.

20616405121 is a deficient number, since it is larger than the sum of its proper divisors (2891894183).

20616405121 is a wasteful number, since it uses less digits than its factorization.

20616405121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 93286931.

The product of its (nonzero) digits is 2880, while the sum is 28.

Adding to 20616405121 its reverse (12150461602), we get a palindrome (32766866723).

The spelling of 20616405121 in words is "twenty billion, six hundred sixteen million, four hundred five thousand, one hundred twenty-one".