20621436 has 48 divisors (see below), whose sum is σ = 54311040. Its totient is φ = 6032320.

The previous prime is 20621431. The next prime is 20621443. The reversal of 20621436 is 63412602.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20621431) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1135 + ... + 6521.

It is an arithmetic number, because the mean of its divisors is an integer number (1131480).

Almost surely, 2^20621436 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 20621436, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27155520).

20621436 is an abundant number, since it is smaller than the sum of its proper divisors (33689604).

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

20621436 is a wasteful number, since it uses less digits than its factorization.

20621436 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5434 (or 5432 counting only the distinct ones).

The product of its (nonzero) digits is 1728, while the sum is 24.

The square root of 20621436 is about 4541.0831307079. The cubic root of 20621436 is about 274.2245304688.

The spelling of 20621436 in words is "twenty million, six hundred twenty-one thousand, four hundred thirty-six".