84921921 has 12 divisors (see below), whose sum is σ = 140188672. Its totient is φ = 48526776.

The previous prime is 84921913. The next prime is 84921923. The reversal of 84921921 is 12912948.

It is not a de Polignac number, because 84921921 - 2³ = 84921913 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (84921923) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 673921 + ... + 674046.

Almost surely, 2^84921921 is an apocalyptic number.

It is an amenable number.

84921921 is a deficient number, since it is larger than the sum of its proper divisors (55266751).

84921921 is a wasteful number, since it uses less digits than its factorization.

84921921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1347980 (or 1347977 counting only the distinct ones).

The product of its digits is 10368, while the sum is 36.

The square root of 84921921 is about 9215.3090561305. The cubic root of 84921921 is about 439.5482984968.

The spelling of 84921921 in words is "eighty-four million, nine hundred twenty-one thousand, nine hundred twenty-one".