20169640 has 32 divisors (see below), whose sum is σ = 47772000. Its totient is φ = 7642944.

The previous prime is 20169637. The next prime is 20169641. The reversal of 20169640 is 4696102.

It is a junction number, because it is equal to n+sod(n) for n = 20169599 and 20169608.

It is not an unprimeable number, because it can be changed into a prime (20169641) 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, 12510 + ... + 14029.

It is an arithmetic number, because the mean of its divisors is an integer number (1492875).

Almost surely, 2^20169640 is an apocalyptic number.

20169640 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20169640 is an abundant number, since it is smaller than the sum of its proper divisors (27602360).

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

20169640 is a wasteful number, since it uses less digits than its factorization.

20169640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 26569 (or 26565 counting only the distinct ones).

The product of its (nonzero) digits is 2592, while the sum is 28.

The square root of 20169640 is about 4491.0622351511. The cubic root of 20169640 is about 272.2070583128.

The spelling of 20169640 in words is "twenty million, one hundred sixty-nine thousand, six hundred forty".