71821947 has 8 divisors (see below), whose sum is σ = 98851840. Its totient is φ = 46336680.

The previous prime is 71821933. The next prime is 71821961. The reversal of 71821947 is 74912817.

It is an interprime number because it is at equal distance from previous prime (71821933) and next prime (71821961).

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 71821947 - 2⁷ = 71821819 is a prime.

It is a super-5 number, since 5×71821947⁵ (a number of 40 digits) contains 55555 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (71821147) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 386047 + ... + 386232.

It is an arithmetic number, because the mean of its divisors is an integer number (12356480).

Almost surely, 2^71821947 is an apocalyptic number.

71821947 is a deficient number, since it is larger than the sum of its proper divisors (27029893).

71821947 is a wasteful number, since it uses less digits than its factorization.

71821947 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 772313.

The product of its digits is 28224, while the sum is 39.

The square root of 71821947 is about 8474.7830060716. The cubic root of 71821947 is about 415.6735508286.

The spelling of 71821947 in words is "seventy-one million, eight hundred twenty-one thousand, nine hundred forty-seven".