87428999 has 4 divisors (see below), whose sum is σ = 99918864. Its totient is φ = 74939136.

The previous prime is 87428989. The next prime is 87429029. The reversal of 87428999 is 99982478.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 99982478 = 2 ⋅49991239.

It is a cyclic number.

It is not a de Polignac number, because 87428999 - 2⁴ = 87428983 is a prime.

It is a super-2 number, since 2×87428999² = 15287659732284002, 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 (87428969) 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, 6244922 + ... + 6244935.

It is an arithmetic number, because the mean of its divisors is an integer number (24979716).

Almost surely, 2^87428999 is an apocalyptic number.

87428999 is a deficient number, since it is larger than the sum of its proper divisors (12489865).

87428999 is a wasteful number, since it uses less digits than its factorization.

87428999 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12489864.

The product of its digits is 2612736, while the sum is 56.

The square root of 87428999 is about 9350.3475336481. The cubic root of 87428999 is about 443.8318882402.

The spelling of 87428999 in words is "eighty-seven million, four hundred twenty-eight thousand, nine hundred ninety-nine".