20616620731 has 4 divisors (see below), whose sum is σ = 23561852272. Its totient is φ = 17671389192.

The previous prime is 20616620707. The next prime is 20616620741. The reversal of 20616620731 is 13702661602.

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 20616620731 - 2⁷ = 20616620603 is a prime.

It is a super-2 number, since 2×20616620731² (a number of 21 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (20616620741) 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, 1472615760 + ... + 1472615773.

It is an arithmetic number, because the mean of its divisors is an integer number (5890463068).

Almost surely, 2^20616620731 is an apocalyptic number.

20616620731 is a deficient number, since it is larger than the sum of its proper divisors (2945231541).

20616620731 is an equidigital number, since it uses as much as digits as its factorization.

20616620731 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2945231540.

The product of its (nonzero) digits is 18144, while the sum is 34.

The spelling of 20616620731 in words is "twenty billion, six hundred sixteen million, six hundred twenty thousand, seven hundred thirty-one".