20918279042 has 4 divisors (see below), whose sum is σ = 31377418566. Its totient is φ = 10459139520.

The previous prime is 20918279033. The next prime is 20918279047. The reversal of 20918279042 is 24097281902.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 24097281902 = 2 ⋅12048640951.

It can be written as a sum of positive squares in only one way, i.e., 20918126161 + 152881 = 144631^2 + 391^2 .

It is a junction number, because it is equal to n+sod(n) for n = 20918278984 and 20918279002.

It is not an unprimeable number, because it can be changed into a prime (20918279047) 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 as a sum of consecutive naturals, namely, 5229569759 + ... + 5229569762.

Almost surely, 2^20918279042 is an apocalyptic number.

20918279042 is a deficient number, since it is larger than the sum of its proper divisors (10459139524).

20918279042 is a wasteful number, since it uses less digits than its factorization.

20918279042 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10459139523.

The product of its (nonzero) digits is 145152, while the sum is 44.

The spelling of 20918279042 in words is "twenty billion, nine hundred eighteen million, two hundred seventy-nine thousand, forty-two".