20425642 has 4 divisors (see below), whose sum is σ = 30638466. Its totient is φ = 10212820.

The previous prime is 20425637. The next prime is 20425673. The reversal of 20425642 is 24652402.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 24652402 = 2 ⋅12326201.

It can be written as a sum of positive squares in only one way, i.e., 13184161 + 7241481 = 3631^2 + 2691^2 .

It is a super-2 number, since 2×20425642² = 834413702224328, which contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5106409 + ... + 5106412.

Almost surely, 2^20425642 is an apocalyptic number.

20425642 is a deficient number, since it is larger than the sum of its proper divisors (10212824).

20425642 is a wasteful number, since it uses less digits than its factorization.

20425642 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10212823.

The product of its (nonzero) digits is 3840, while the sum is 25.

The square root of 20425642 is about 4519.4736419189. The cubic root of 20425642 is about 273.3538774300.

The spelling of 20425642 in words is "twenty million, four hundred twenty-five thousand, six hundred forty-two".