42103721 has 4 divisors (see below), whose sum is σ = 45931344. Its totient is φ = 38276100.

The previous prime is 42103703. The next prime is 42103727. The reversal of 42103721 is 12730124.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 42103721 - 2⁶ = 42103657 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 42103693 and 42103702.

It is not an unprimeable number, because it can be changed into a prime (42103727) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1913795 + ... + 1913816.

It is an arithmetic number, because the mean of its divisors is an integer number (11482836).

Almost surely, 2^42103721 is an apocalyptic number.

It is an amenable number.

42103721 is a deficient number, since it is larger than the sum of its proper divisors (3827623).

42103721 is a wasteful number, since it uses less digits than its factorization.

42103721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3827622.

The product of its (nonzero) digits is 336, while the sum is 20.

The square root of 42103721 is about 6488.7380128959. The cubic root of 42103721 is about 347.8885697096. Note that the first 3 decimals are identical.

Adding to 42103721 its reverse (12730124), we get a palindrome (54833845).

It can be divided in two parts, 42103 and 721, that added together give a palindrome (42824).

The spelling of 42103721 in words is "forty-two million, one hundred three thousand, seven hundred twenty-one".