84542981 has 2 divisors, whose sum is σ = 84542982. Its totient is φ = 84542980.

The previous prime is 84542923. The next prime is 84542987. The reversal of 84542981 is 18924548.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 83429956 + 1113025 = 9134^2 + 1055^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-84542981 is a prime.

It is a super-2 number, since 2×84542981² = 14295031272732722, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (84542987) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 42271490 + 42271491.

It is an arithmetic number, because the mean of its divisors is an integer number (42271491).

Almost surely, 2^84542981 is an apocalyptic number.

It is an amenable number.

84542981 is a deficient number, since it is larger than the sum of its proper divisors (1).

84542981 is an equidigital number, since it uses as much as digits as its factorization.

84542981 is an evil number, because the sum of its binary digits is even.

The product of its digits is 92160, while the sum is 41.

The square root of 84542981 is about 9194.7257164094. The cubic root of 84542981 is about 438.8935370715.

The spelling of 84542981 in words is "eighty-four million, five hundred forty-two thousand, nine hundred eighty-one".