42721847 has 4 divisors (see below), whose sum is σ = 48824976. Its totient is φ = 36618720.

The previous prime is 42721801. The next prime is 42721849. The reversal of 42721847 is 74812724.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-42721847 is a prime.

It is a super-2 number, since 2×42721847² = 3650312422182818, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (42721849) 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, 3051554 + ... + 3051567.

It is an arithmetic number, because the mean of its divisors is an integer number (12206244).

Almost surely, 2^42721847 is an apocalyptic number.

42721847 is a deficient number, since it is larger than the sum of its proper divisors (6103129).

42721847 is an equidigital number, since it uses as much as digits as its factorization.

42721847 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6103128.

The product of its digits is 25088, while the sum is 35.

The square root of 42721847 is about 6536.1951470255. The cubic root of 42721847 is about 349.5827599426.

The spelling of 42721847 in words is "forty-two million, seven hundred twenty-one thousand, eight hundred forty-seven".