84497721 has 16 divisors (see below), whose sum is σ = 140464128. Its totient is φ = 43894800.

The previous prime is 84497717. The next prime is 84497729. The reversal of 84497721 is 12779448.

It is a happy number.

It is not a de Polignac number, because 84497721 - 2² = 84497717 is a prime.

It is not an unprimeable number, because it can be changed into a prime (84497729) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 182665 + ... + 183126.

It is an arithmetic number, because the mean of its divisors is an integer number (8779008).

Almost surely, 2^84497721 is an apocalyptic number.

It is an amenable number.

84497721 is a deficient number, since it is larger than the sum of its proper divisors (55966407).

84497721 is a wasteful number, since it uses less digits than its factorization.

84497721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 365812.

The product of its digits is 112896, while the sum is 42.

The square root of 84497721 is about 9192.2641933313. The cubic root of 84497721 is about 438.8152026863.

The spelling of 84497721 in words is "eighty-four million, four hundred ninety-seven thousand, seven hundred twenty-one".