20611655651 has 4 divisors (see below), whose sum is σ = 20615288232. Its totient is φ = 20608023072.

The previous prime is 20611655569. The next prime is 20611655711. The reversal of 20611655651 is 15655611602.

It is a happy number.

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

It is a cyclic number.

It is not a de Polignac number, because 20611655651 - 2³⁴ = 3431786467 is a prime.

It is a super-3 number, since 3×20611655651³ (a number of 32 digits) contains 333 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20611645651) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1807766 + ... + 1819131.

It is an arithmetic number, because the mean of its divisors is an integer number (5153822058).

Almost surely, 2^20611655651 is an apocalyptic number.

20611655651 is a deficient number, since it is larger than the sum of its proper divisors (3632581).

20611655651 is an equidigital number, since it uses as much as digits as its factorization.

20611655651 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3632580.

The product of its (nonzero) digits is 54000, while the sum is 38.

The spelling of 20611655651 in words is "twenty billion, six hundred eleven million, six hundred fifty-five thousand, six hundred fifty-one".