20985738 has 8 divisors (see below), whose sum is σ = 41971488. Its totient is φ = 6995244.

The previous prime is 20985737. The next prime is 20985739. The reversal of 20985738 is 83758902.

It is an interprime number because it is at equal distance from previous prime (20985737) and next prime (20985739).

It is a sphenic number, since it is the product of 3 distinct primes.

20985738 is an admirable number.

It is a self number, because there is not a number n which added to its sum of digits gives 20985738.

It is not an unprimeable number, because it can be changed into a prime (20985737) 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, 1748806 + ... + 1748817.

It is an arithmetic number, because the mean of its divisors is an integer number (5246436).

Almost surely, 2^20985738 is an apocalyptic number.

20985738 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

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

20985738 is a wasteful number, since it uses less digits than its factorization.

20985738 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3497628.

The product of its (nonzero) digits is 120960, while the sum is 42.

The square root of 20985738 is about 4581.0193188853. The cubic root of 20985738 is about 275.8299467055.

The spelling of 20985738 in words is "twenty million, nine hundred eighty-five thousand, seven hundred thirty-eight".