20673987 has 8 divisors (see below), whose sum is σ = 28763904. Its totient is φ = 13183368.

The previous prime is 20673977. The next prime is 20673997. The reversal of 20673987 is 78937602.

It is an interprime number because it is at equal distance from previous prime (20673977) and next prime (20673997).

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

It is not a de Polignac number, because 20673987 - 2⁴ = 20673971 is a prime.

It is not an unprimeable number, because it can be changed into a prime (20673907) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 149743 + ... + 149880.

It is an arithmetic number, because the mean of its divisors is an integer number (3595488).

Almost surely, 2^20673987 is an apocalyptic number.

20673987 is a deficient number, since it is larger than the sum of its proper divisors (8089917).

20673987 is a wasteful number, since it uses less digits than its factorization.

20673987 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 299649.

The product of its (nonzero) digits is 127008, while the sum is 42.

The square root of 20673987 is about 4546.8656237017. The cubic root of 20673987 is about 274.4572745138.

The spelling of 20673987 in words is "twenty million, six hundred seventy-three thousand, nine hundred eighty-seven".