81722049 has 16 divisors (see below), whose sum is σ = 112637952. Its totient is φ = 52672208.

The previous prime is 81722027. The next prime is 81722057. The reversal of 81722049 is 94022718.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 81722049 - 2¹³ = 81713857 is a prime.

It is not an unprimeable number, because it can be changed into a prime (81722099) 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, 8212 + ... + 15194.

It is an arithmetic number, because the mean of its divisors is an integer number (7039872).

Almost surely, 2^81722049 is an apocalyptic number.

It is an amenable number.

81722049 is a deficient number, since it is larger than the sum of its proper divisors (30915903).

81722049 is a wasteful number, since it uses less digits than its factorization.

81722049 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7116.

The product of its (nonzero) digits is 8064, while the sum is 33.

The square root of 81722049 is about 9040.0248340367. The cubic root of 81722049 is about 433.9567177065.

The spelling of 81722049 in words is "eighty-one million, seven hundred twenty-two thousand, forty-nine".