20442531 has 8 divisors (see below), whose sum is σ = 27437824. Its totient is φ = 13537800.

The previous prime is 20442523. The next prime is 20442557. The reversal of 20442531 is 13524402.

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

It is not a de Polignac number, because 20442531 - 2³ = 20442523 is a prime.

It is a super-2 number, since 2×20442531² = 835794147371922, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 20442498 and 20442507.

It is not an unprimeable number, because it can be changed into a prime (20442511) 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, 22111 + ... + 23016.

It is an arithmetic number, because the mean of its divisors is an integer number (3429728).

Almost surely, 2^20442531 is an apocalyptic number.

20442531 is a deficient number, since it is larger than the sum of its proper divisors (6995293).

20442531 is a wasteful number, since it uses less digits than its factorization.

20442531 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 45281.

The product of its (nonzero) digits is 960, while the sum is 21.

The square root of 20442531 is about 4521.3417256385. The cubic root of 20442531 is about 273.4291978170.

Adding to 20442531 its reverse (13524402), we get a palindrome (33966933).

The spelling of 20442531 in words is "twenty million, four hundred forty-two thousand, five hundred thirty-one".