20342540 has 96 divisors (see below), whose sum is σ = 49351680. Its totient is φ = 6994944.

The previous prime is 20342537. The next prime is 20342573. The reversal of 20342540 is 4524302.

It is a Harshad number since it is a multiple of its sum of digits (20).

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 303587 + ... + 303653.

It is an arithmetic number, because the mean of its divisors is an integer number (514080).

Almost surely, 2^20342540 is an apocalyptic number.

20342540 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 20342540, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24675840).

20342540 is an abundant number, since it is smaller than the sum of its proper divisors (29009140).

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

20342540 is a wasteful number, since it uses less digits than its factorization.

20342540 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 159 (or 157 counting only the distinct ones).

The product of its (nonzero) digits is 960, while the sum is 20.

The square root of 20342540 is about 4510.2705018657. The cubic root of 20342540 is about 272.9826588922.

Adding to 20342540 its reverse (4524302), we get a palindrome (24866842).

The spelling of 20342540 in words is "twenty million, three hundred forty-two thousand, five hundred forty".