87840057 has 4 divisors (see below), whose sum is σ = 117120080. Its totient is φ = 58560036.

The previous prime is 87840041. The next prime is 87840083. The reversal of 87840057 is 75004878.

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 not a de Polignac number, because 87840057 - 2⁴ = 87840041 is a prime.

It is a super-2 number, since 2×87840057² = 15431751227526498, 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 = 87839997 and 87840024.

It is not an unprimeable number, because it can be changed into a prime (87840017) 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, 14640007 + ... + 14640012.

It is an arithmetic number, because the mean of its divisors is an integer number (29280020).

Almost surely, 2^87840057 is an apocalyptic number.

It is an amenable number.

87840057 is a deficient number, since it is larger than the sum of its proper divisors (29280023).

87840057 is a wasteful number, since it uses less digits than its factorization.

87840057 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 29280022.

The product of its (nonzero) digits is 62720, while the sum is 39.

The square root of 87840057 is about 9372.3026519634. The cubic root of 87840057 is about 444.5263773786.

The spelling of 87840057 in words is "eighty-seven million, eight hundred forty thousand, fifty-seven".