71972181 has 24 divisors (see below), whose sum is σ = 106778880. Its totient is φ = 46692576.

The previous prime is 71972167. The next prime is 71972183. The reversal of 71972181 is 18127917.

It is not a de Polignac number, because 71972181 - 2⁷ = 71972053 is a prime.

It is a super-2 number, since 2×71972181² = 10359989675793522, which contains 22 as substring.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (71972183) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 96496 + ... + 97238.

It is an arithmetic number, because the mean of its divisors is an integer number (4449120).

Almost surely, 2^71972181 is an apocalyptic number.

It is an amenable number.

71972181 is a deficient number, since it is larger than the sum of its proper divisors (34806699).

71972181 is a wasteful number, since it uses less digits than its factorization.

71972181 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1025 (or 1022 counting only the distinct ones).

The product of its digits is 7056, while the sum is 36.

The square root of 71972181 is about 8483.6419655712. The cubic root of 71972181 is about 415.9631782158.

It can be divided in two parts, 719 and 72181, that added together give a square (72900 = 270²).

The spelling of 71972181 in words is "seventy-one million, nine hundred seventy-two thousand, one hundred eighty-one".