20757540 has 48 divisors (see below), whose sum is σ = 58347072. Its totient is φ = 5513856.

The previous prime is 20757511. The next prime is 20757577. The reversal of 20757540 is 4575702.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a junction number, because it is equal to n+sod(n) for n = 20757498 and 20757507.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 20322 + ... + 21318.

It is an arithmetic number, because the mean of its divisors is an integer number (1215564).

Almost surely, 2^20757540 is an apocalyptic number.

20757540 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20757540 is an abundant number, since it is smaller than the sum of its proper divisors (37589532).

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

20757540 is a wasteful number, since it uses less digits than its factorization.

20757540 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1356 (or 1354 counting only the distinct ones).

The product of its (nonzero) digits is 9800, while the sum is 30.

The square root of 20757540 is about 4556.0443369221. The cubic root of 20757540 is about 274.8265131664.

The spelling of 20757540 in words is "twenty million, seven hundred fifty-seven thousand, five hundred forty".