20611807381 has 4 divisors (see below), whose sum is σ = 22485608064. Its totient is φ = 18738006700.

The previous prime is 20611807357. The next prime is 20611807399. The reversal of 20611807381 is 18370811602.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 20611807381 - 2⁷ = 20611807253 is a prime.

It is a super-2 number, since 2×20611807381² (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 20611807381.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20611808381) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 936900325 + ... + 936900346.

It is an arithmetic number, because the mean of its divisors is an integer number (5621402016).

Almost surely, 2^20611807381 is an apocalyptic number.

It is an amenable number.

20611807381 is a deficient number, since it is larger than the sum of its proper divisors (1873800683).

20611807381 is a wasteful number, since it uses less digits than its factorization.

20611807381 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1873800682.

The product of its (nonzero) digits is 16128, while the sum is 37.

The spelling of 20611807381 in words is "twenty billion, six hundred eleven million, eight hundred seven thousand, three hundred eighty-one".