20616511255 has 4 divisors (see below), whose sum is σ = 24739813512. Its totient is φ = 16493209000.

The previous prime is 20616511243. The next prime is 20616511261. The reversal of 20616511255 is 55211561602.

It is a semiprime because it is the product of two primes.

It is a de Polignac number, because none of the positive numbers 2^k-20616511255 is a prime.

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 20616511255.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2061651121 + ... + 2061651130.

It is an arithmetic number, because the mean of its divisors is an integer number (6184953378).

Almost surely, 2^20616511255 is an apocalyptic number.

20616511255 is a deficient number, since it is larger than the sum of its proper divisors (4123302257).

20616511255 is an equidigital number, since it uses as much as digits as its factorization.

20616511255 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4123302256.

The product of its (nonzero) digits is 18000, while the sum is 34.

The spelling of 20616511255 in words is "twenty billion, six hundred sixteen million, five hundred eleven thousand, two hundred fifty-five".