20433640 has 32 divisors (see below), whose sum is σ = 46125000. Its totient is φ = 8146944.

The previous prime is 20433629. The next prime is 20433641. The reversal of 20433640 is 4633402.

It can be written as a sum of positive squares in 4 ways, for example, as 19027044 + 1406596 = 4362^2 + 1186^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20433641) 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, 15736 + ... + 16984.

Almost surely, 2^20433640 is an apocalyptic number.

20433640 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20433640 is an abundant number, since it is smaller than the sum of its proper divisors (25691360).

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

20433640 is a wasteful number, since it uses less digits than its factorization.

20433640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1669 (or 1665 counting only the distinct ones).

The product of its (nonzero) digits is 1728, while the sum is 22.

The square root of 20433640 is about 4520.3583928711. The cubic root of 20433640 is about 273.3895515272.

The spelling of 20433640 in words is "twenty million, four hundred thirty-three thousand, six hundred forty".