84009551 has 4 divisors (see below), whose sum is σ = 84177072. Its totient is φ = 83842032.

The previous prime is 84009493. The next prime is 84009559. The reversal of 84009551 is 15590048.

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 84009551 - 2¹⁰ = 84008527 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (84009559) 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, 83006 + ... + 84011.

It is an arithmetic number, because the mean of its divisors is an integer number (21044268).

Almost surely, 2^84009551 is an apocalyptic number.

84009551 is a deficient number, since it is larger than the sum of its proper divisors (167521).

84009551 is a wasteful number, since it uses less digits than its factorization.

84009551 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 167520.

The product of its (nonzero) digits is 7200, while the sum is 32.

The square root of 84009551 is about 9165.6724248688. The cubic root of 84009551 is about 437.9685120848.

Adding to 84009551 its reverse (15590048), we get a palindrome (99599599).

The spelling of 84009551 in words is "eighty-four million, nine thousand, five hundred fifty-one".