20426342781 has 32 divisors (see below), whose sum is σ = 29506514688. Its totient is φ = 12494684160.

The previous prime is 20426342771. The next prime is 20426342791. The reversal of 20426342781 is 18724362402.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (20426342771) and next prime (20426342791).

It is not a de Polignac number, because 20426342781 - 2⁷ = 20426342653 is a prime.

It is a super-2 number, since 2×20426342781² (a number of 21 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (39).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20426342771) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 5420560 + ... + 5424326.

It is an arithmetic number, because the mean of its divisors is an integer number (922078584).

Almost surely, 2^20426342781 is an apocalyptic number.

It is an amenable number.

20426342781 is a deficient number, since it is larger than the sum of its proper divisors (9080171907).

20426342781 is a wasteful number, since it uses less digits than its factorization.

20426342781 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4581.

The product of its (nonzero) digits is 129024, while the sum is 39.

The spelling of 20426342781 in words is "twenty billion, four hundred twenty-six million, three hundred forty-two thousand, seven hundred eighty-one".