71634421 has 4 divisors (see below), whose sum is σ = 73381644. Its totient is φ = 69887200.

The previous prime is 71634391. The next prime is 71634461. The reversal of 71634421 is 12443617.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 12443617 = 31 ⋅401407.

It can be written as a sum of positive squares in 2 ways, for example, as 36469521 + 35164900 = 6039^2 + 5930^2 .

It is a cyclic number.

It is not a de Polignac number, because 71634421 - 2¹³ = 71626229 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 71634421.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (71634461) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 873550 + ... + 873631.

It is an arithmetic number, because the mean of its divisors is an integer number (18345411).

Almost surely, 2^71634421 is an apocalyptic number.

It is an amenable number.

71634421 is a deficient number, since it is larger than the sum of its proper divisors (1747223).

71634421 is a wasteful number, since it uses less digits than its factorization.

71634421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1747222.

The product of its digits is 4032, while the sum is 28.

The square root of 71634421 is about 8463.7120106960. The cubic root of 71634421 is about 415.3114630924.

The spelling of 71634421 in words is "seventy-one million, six hundred thirty-four thousand, four hundred twenty-one".