20739240 has 160 divisors (see below), whose sum is σ = 72004680. Its totient is φ = 5349888.

The previous prime is 20739233. The next prime is 20739253. The reversal of 20739240 is 4293702.

It can be written as a sum of positive squares in 4 ways, for example, as 20738916 + 324 = 4554^2 + 18^2 .

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 39 ways as a sum of consecutive naturals, for example, 119794 + ... + 119966.

Almost surely, 2^20739240 is an apocalyptic number.

20739240 is a gapful number since it is divisible by the number (20) 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 20739240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (36002340).

20739240 is an abundant number, since it is smaller than the sum of its proper divisors (51265440).

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

20739240 is a wasteful number, since it uses less digits than its factorization.

20739240 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 233 (or 220 counting only the distinct ones).

The product of its (nonzero) digits is 3024, while the sum is 27.

The square root of 20739240 is about 4554.0355729836. The cubic root of 20739240 is about 274.7457263956.

The spelling of 20739240 in words is "twenty million, seven hundred thirty-nine thousand, two hundred forty".