20919700243 has 4 divisors (see below), whose sum is σ = 22528907968. Its totient is φ = 19310492520.

The previous prime is 20919700237. The next prime is 20919700247. The reversal of 20919700243 is 34200791902.

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 20919700243 - 2²⁵ = 20886145811 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20919700247) 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, 804603843 + ... + 804603868.

It is an arithmetic number, because the mean of its divisors is an integer number (5632226992).

Almost surely, 2^20919700243 is an apocalyptic number.

20919700243 is a deficient number, since it is larger than the sum of its proper divisors (1609207725).

20919700243 is a wasteful number, since it uses less digits than its factorization.

20919700243 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1609207724.

The product of its (nonzero) digits is 27216, while the sum is 37.

The spelling of 20919700243 in words is "twenty billion, nine hundred nineteen million, seven hundred thousand, two hundred forty-three".