20409624 has 64 divisors (see below), whose sum is σ = 57660000. Its totient is φ = 6687360.

The previous prime is 20409601. The next prime is 20409643. The reversal of 20409624 is 42690402.

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 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, 12402 + ... + 13950.

Almost surely, 2^20409624 is an apocalyptic number.

20409624 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20409624, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28830000).

20409624 is an abundant number, since it is smaller than the sum of its proper divisors (37250376).

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

20409624 is a wasteful number, since it uses less digits than its factorization.

20409624 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1625 (or 1615 counting only the distinct ones).

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

The square root of 20409624 is about 4517.7011853375. The cubic root of 20409624 is about 273.2824030959.

It can be divided in two parts, 2040 and 9624, that added together give a square (11664 = 108²).

The spelling of 20409624 in words is "twenty million, four hundred nine thousand, six hundred twenty-four".