20761540 has 12 divisors (see below), whose sum is σ = 43599276. Its totient is φ = 8304608.

The previous prime is 20761529. The next prime is 20761541. The reversal of 20761540 is 4516702.

It can be written as a sum of positive squares in 2 ways, for example, as 10876804 + 9884736 = 3298^2 + 3144^2 .

It is not an unprimeable number, because it can be changed into a prime (20761541) 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 3 ways as a sum of consecutive naturals, for example, 519019 + ... + 519058.

It is an arithmetic number, because the mean of its divisors is an integer number (3633273).

Almost surely, 2^20761540 is an apocalyptic number.

20761540 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20761540 is an abundant number, since it is smaller than the sum of its proper divisors (22837736).

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

20761540 is a wasteful number, since it uses less digits than its factorization.

20761540 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1038086 (or 1038084 counting only the distinct ones).

The product of its (nonzero) digits is 1680, while the sum is 25.

The square root of 20761540 is about 4556.4832930671. The cubic root of 20761540 is about 274.8441651529.

The spelling of 20761540 in words is "twenty million, seven hundred sixty-one thousand, five hundred forty".