20781732394 has 16 divisors (see below), whose sum is σ = 31577364000. Its totient is φ = 10256176240.

The previous prime is 20781732371. The next prime is 20781732397. The reversal of 20781732394 is 49323718702.

It is not an unprimeable number, because it can be changed into a prime (20781732397) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 123732 + ... + 238480.

It is an arithmetic number, because the mean of its divisors is an integer number (1973585250).

Almost surely, 2^20781732394 is an apocalyptic number.

20781732394 is a deficient number, since it is larger than the sum of its proper divisors (10795631606).

20781732394 is a wasteful number, since it uses less digits than its factorization.

20781732394 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 115925.

The product of its (nonzero) digits is 508032, while the sum is 46.

The spelling of 20781732394 in words is "twenty billion, seven hundred eighty-one million, seven hundred thirty-two thousand, three hundred ninety-four".