16820542 has 4 divisors (see below), whose sum is σ = 25230816. Its totient is φ = 8410270.

The previous prime is 16820527. The next prime is 16820549. The reversal of 16820542 is 24502861.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 24502861 = 137 ⋅178853.

It is a self number, because there is not a number n which added to its sum of digits gives 16820542.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (16820549) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4205134 + ... + 4205137.

It is an arithmetic number, because the mean of its divisors is an integer number (6307704).

Almost surely, 2^16820542 is an apocalyptic number.

16820542 is a deficient number, since it is larger than the sum of its proper divisors (8410274).

16820542 is an equidigital number, since it uses as much as digits as its factorization.

16820542 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8410273.

The product of its (nonzero) digits is 3840, while the sum is 28.

The square root of 16820542 is about 4101.2854082592. The cubic root of 16820542 is about 256.2201780088.

The spelling of 16820542 in words is "sixteen million, eight hundred twenty thousand, five hundred forty-two".