20012433640 has 16 divisors (see below), whose sum is σ = 45027975780. Its totient is φ = 8004973440.

The previous prime is 20012433629. The next prime is 20012433647. The reversal of 20012433640 is 4633421002.

It can be written as a sum of positive squares in 2 ways, for example, as 19971907684 + 40525956 = 141322^2 + 6366^2 .

It is not an unprimeable number, because it can be changed into a prime (20012433647) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 250155381 + ... + 250155460.

Almost surely, 2^20012433640 is an apocalyptic number.

20012433640 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20012433640 is an abundant number, since it is smaller than the sum of its proper divisors (25015542140).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

20012433640 is a wasteful number, since it uses less digits than its factorization.

20012433640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 500310852 (or 500310848 counting only the distinct ones).

The product of its (nonzero) digits is 3456, while the sum is 25.

Adding to 20012433640 its reverse (4633421002), we get a palindrome (24645854642).

The spelling of 20012433640 in words is "twenty billion, twelve million, four hundred thirty-three thousand, six hundred forty".