20642138 has 8 divisors (see below), whose sum is σ = 33778080. Its totient is φ = 9382780.

The previous prime is 20642129. The next prime is 20642161. The reversal of 20642138 is 83124602.

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

It is a super-2 number, since 2×20642138² = 852195722422088, which contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 469118 + ... + 469161.

It is an arithmetic number, because the mean of its divisors is an integer number (4222260).

Almost surely, 2^20642138 is an apocalyptic number.

20642138 is a deficient number, since it is larger than the sum of its proper divisors (13135942).

20642138 is a wasteful number, since it uses less digits than its factorization.

20642138 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 938292.

The product of its (nonzero) digits is 2304, while the sum is 26.

The square root of 20642138 is about 4543.3619710518. The cubic root of 20642138 is about 274.3162650690.

The spelling of 20642138 in words is "twenty million, six hundred forty-two thousand, one hundred thirty-eight".