20742015 has 64 divisors (see below), whose sum is σ = 41149440. Its totient is φ = 8709120.

The previous prime is 20741947. The next prime is 20742017. The reversal of 20742015 is 51024702.

It is not a de Polignac number, because 20742015 - 2⁹ = 20741503 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (21).

It is a junction number, because it is equal to n+sod(n) for n = 20741982 and 20742000.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20742017) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 73675 + ... + 73955.

It is an arithmetic number, because the mean of its divisors is an integer number (642960).

Almost surely, 2^20742015 is an apocalyptic number.

20742015 is a deficient number, since it is larger than the sum of its proper divisors (20407425).

20742015 is a wasteful number, since it uses less digits than its factorization.

20742015 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 352.

The product of its (nonzero) digits is 560, while the sum is 21.

The square root of 20742015 is about 4554.3402376195. The cubic root of 20742015 is about 274.7579799046.

20742015 divided by its sum of digits (21) gives a triangular number (987715 = T₁₄₀₅).

Adding to 20742015 its reverse (51024702), we get a palindrome (71766717).

The spelling of 20742015 in words is "twenty million, seven hundred forty-two thousand, fifteen".