71722561 has 4 divisors (see below), whose sum is σ = 74036224. Its totient is φ = 69408900.

The previous prime is 71722559. The next prime is 71722603. The reversal of 71722561 is 16522717.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 16522717 = 23 ⋅718379.

It is a cyclic number.

It is not a de Polignac number, because 71722561 - 2¹ = 71722559 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (31), and also a Moran number because the ratio is a prime number: 2313631 = 71722561 / (7 + 1 + 7 + 2 + 2 + 5 + 6 + 1).

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (71722501) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1156785 + ... + 1156846.

It is an arithmetic number, because the mean of its divisors is an integer number (18509056).

Almost surely, 2^71722561 is an apocalyptic number.

It is an amenable number.

71722561 is a deficient number, since it is larger than the sum of its proper divisors (2313663).

71722561 is a wasteful number, since it uses less digits than its factorization.

71722561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2313662.

The product of its digits is 5880, while the sum is 31.

The square root of 71722561 is about 8468.9173452101. The cubic root of 71722561 is about 415.4817283027.

The spelling of 71722561 in words is "seventy-one million, seven hundred twenty-two thousand, five hundred sixty-one".