20720253989 has 4 divisors (see below), whose sum is σ = 20731224780. Its totient is φ = 20709283200.

The previous prime is 20720253979. The next prime is 20720254001. The reversal of 20720253989 is 98935202702.

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

It can be written as a sum of positive squares in 2 ways, for example, as 12902688100 + 7817565889 = 113590^2 + 88417^2 .

It is a cyclic number.

It is not a de Polignac number, because 20720253989 - 2⁸ = 20720253733 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20720253919) 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, 5482562 + ... + 5486339.

It is an arithmetic number, because the mean of its divisors is an integer number (5182806195).

Almost surely, 2^20720253989 is an apocalyptic number.

It is an amenable number.

20720253989 is a deficient number, since it is larger than the sum of its proper divisors (10970791).

20720253989 is a wasteful number, since it uses less digits than its factorization.

20720253989 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10970790.

The product of its (nonzero) digits is 544320, while the sum is 47.

The spelling of 20720253989 in words is "twenty billion, seven hundred twenty million, two hundred fifty-three thousand, nine hundred eighty-nine".