20782949 has 4 divisors (see below), whose sum is σ = 22672320. Its totient is φ = 18893580.

The previous prime is 20782939. The next prime is 20782969. The reversal of 20782949 is 94928702.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 20782949 - 2⁸ = 20782693 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20782919) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 944669 + ... + 944690.

It is an arithmetic number, because the mean of its divisors is an integer number (5668080).

Almost surely, 2^20782949 is an apocalyptic number.

It is an amenable number.

20782949 is a deficient number, since it is larger than the sum of its proper divisors (1889371).

20782949 is a wasteful number, since it uses less digits than its factorization.

20782949 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1889370.

The product of its (nonzero) digits is 72576, while the sum is 41.

The square root of 20782949 is about 4558.8319776013. The cubic root of 20782949 is about 274.9386044759.

Subtracting 20782949 from its reverse (94928702), we obtain a triangular number (74145753 = T₁₂₁₇₇).

The spelling of 20782949 in words is "twenty million, seven hundred eighty-two thousand, nine hundred forty-nine".