20402642 has 8 divisors (see below), whose sum is σ = 32958156. Its totient is φ = 9416592.

The previous prime is 20402623. The next prime is 20402647. The reversal of 20402642 is 24620402.

It can be written as a sum of positive squares in 2 ways, for example, as 20259001 + 143641 = 4501^2 + 379^2 .

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

It is not an unprimeable number, because it can be changed into a prime (20402647) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 392333 + ... + 392384.

Almost surely, 2^20402642 is an apocalyptic number.

20402642 is a deficient number, since it is larger than the sum of its proper divisors (12555514).

20402642 is a wasteful number, since it uses less digits than its factorization.

20402642 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 784732.

The product of its (nonzero) digits is 768, while the sum is 20.

The square root of 20402642 is about 4516.9283811015. The cubic root of 20402642 is about 273.2512368291.

The spelling of 20402642 in words is "twenty million, four hundred two thousand, six hundred forty-two".