20634540 has 48 divisors (see below), whose sum is σ = 58007040. Its totient is φ = 5480640.

The previous prime is 20634533. The next prime is 20634541. The reversal of 20634540 is 4543602.

It is a self number, because there is not a number n which added to its sum of digits gives 20634540.

It is not an unprimeable number, because it can be changed into a prime (20634541) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 19341 + ... + 20379.

It is an arithmetic number, because the mean of its divisors is an integer number (1208480).

Almost surely, 2^20634540 is an apocalyptic number.

20634540 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20634540 is an abundant number, since it is smaller than the sum of its proper divisors (37372500).

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

20634540 is a wasteful number, since it uses less digits than its factorization.

20634540 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1382 (or 1380 counting only the distinct ones).

The product of its (nonzero) digits is 2880, while the sum is 24.

The square root of 20634540 is about 4542.5257291511. The cubic root of 20634540 is about 274.2826039764.

The spelling of 20634540 in words is "twenty million, six hundred thirty-four thousand, five hundred forty".