87840431 has 4 divisors (see below), whose sum is σ = 100389072. Its totient is φ = 75291792.

The previous prime is 87840373. The next prime is 87840461. The reversal of 87840431 is 13404878.

It is a happy number.

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

It is a cyclic number.

It is not a de Polignac number, because 87840431 - 2²² = 83646127 is a prime.

It is a super-3 number, since 3×87840431³ (a number of 25 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a junction number, because it is equal to n+sod(n) for n = 87840391 and 87840400.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (87840461) 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, 6274310 + ... + 6274323.

It is an arithmetic number, because the mean of its divisors is an integer number (25097268).

Almost surely, 2^87840431 is an apocalyptic number.

87840431 is a deficient number, since it is larger than the sum of its proper divisors (12548641).

87840431 is a wasteful number, since it uses less digits than its factorization.

87840431 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12548640.

The product of its (nonzero) digits is 21504, while the sum is 35.

The square root of 87840431 is about 9372.3226043495. The cubic root of 87840431 is about 444.5270082701.

The spelling of 87840431 in words is "eighty-seven million, eight hundred forty thousand, four hundred thirty-one".