81022649 has 2 divisors, whose sum is σ = 81022650. Its totient is φ = 81022648.

The previous prime is 81022633. The next prime is 81022679. The reversal of 81022649 is 94622018.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 43138624 + 37884025 = 6568^2 + 6155^2 .

It is a cyclic number.

It is not a de Polignac number, because 81022649 - 2⁴ = 81022633 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (81022679) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40511324 + 40511325.

It is an arithmetic number, because the mean of its divisors is an integer number (40511325).

Almost surely, 2^81022649 is an apocalyptic number.

It is an amenable number.

81022649 is a deficient number, since it is larger than the sum of its proper divisors (1).

81022649 is an equidigital number, since it uses as much as digits as its factorization.

81022649 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 6912, while the sum is 32.

The square root of 81022649 is about 9001.2581898310. The cubic root of 81022649 is about 432.7151951248.

The spelling of 81022649 in words is "eighty-one million, twenty-two thousand, six hundred forty-nine".