20813436 has 216 divisors, whose sum is σ = 69713280. Its totient is φ = 5388768.

The previous prime is 20813399. The next prime is 20813447. The reversal of 20813436 is 63431802.

It is a happy number.

It is a hoax number, since the sum of its digits (27) coincides with the sum of the digits of its distinct prime factors.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 904921 + ... + 904943.

Almost surely, 2^20813436 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20813436, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (34856640).

20813436 is an abundant number, since it is smaller than the sum of its proper divisors (48899844).

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

20813436 is a wasteful number, since it uses less digits than its factorization.

20813436 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 75 (or 54 counting only the distinct ones).

The product of its (nonzero) digits is 3456, while the sum is 27.

The square root of 20813436 is about 4562.1744815384. The cubic root of 20813436 is about 275.0729767757.

The spelling of 20813436 in words is "twenty million, eight hundred thirteen thousand, four hundred thirty-six".