20172042 has 24 divisors (see below), whose sum is σ = 47679840. Its totient is φ = 6112680.

The previous prime is 20172037. The next prime is 20172073. The reversal of 20172042 is 24027102.

It is a super-2 number, since 2×20172042² = 813822556899528, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 50742 + ... + 51137.

It is an arithmetic number, because the mean of its divisors is an integer number (1986660).

Almost surely, 2^20172042 is an apocalyptic number.

20172042 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

20172042 is an abundant number, since it is smaller than the sum of its proper divisors (27507798).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

20172042 is a wasteful number, since it uses less digits than its factorization.

20172042 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 101898 (or 101895 counting only the distinct ones).

The product of its (nonzero) digits is 224, while the sum is 18.

The square root of 20172042 is about 4491.3296472203. The cubic root of 20172042 is about 272.2178635858.

Adding to 20172042 its reverse (24027102), we get a palindrome (44199144).

The spelling of 20172042 in words is "twenty million, one hundred seventy-two thousand, forty-two".