87421591 has 2 divisors, whose sum is σ = 87421592. Its totient is φ = 87421590.

The previous prime is 87421577. The next prime is 87421669. The reversal of 87421591 is 19512478.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 87421591 - 2¹⁹ = 86897303 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 87421591.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (87421501) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 43710795 + 43710796.

It is an arithmetic number, because the mean of its divisors is an integer number (43710796).

Almost surely, 2^87421591 is an apocalyptic number.

87421591 is a deficient number, since it is larger than the sum of its proper divisors (1).

87421591 is an equidigital number, since it uses as much as digits as its factorization.

87421591 is an evil number, because the sum of its binary digits is even.

The product of its digits is 20160, while the sum is 37.

The square root of 87421591 is about 9349.9513902480. The cubic root of 87421591 is about 443.8193523557.

The spelling of 87421591 in words is "eighty-seven million, four hundred twenty-one thousand, five hundred ninety-one".