71721634 has 4 divisors (see below), whose sum is σ = 107582454. Its totient is φ = 35860816.

The previous prime is 71721563. The next prime is 71721649. The reversal of 71721634 is 43612717.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 68310225 + 3411409 = 8265^2 + 1847^2 .

It is a junction number, because it is equal to n+sod(n) for n = 71721596 and 71721605.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 17930407 + ... + 17930410.

Almost surely, 2^71721634 is an apocalyptic number.

71721634 is a deficient number, since it is larger than the sum of its proper divisors (35860820).

71721634 is a wasteful number, since it uses less digits than its factorization.

71721634 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 35860819.

The product of its digits is 7056, while the sum is 31.

The square root of 71721634 is about 8468.8626154874. The cubic root of 71721634 is about 415.4799382885.

The spelling of 71721634 in words is "seventy-one million, seven hundred twenty-one thousand, six hundred thirty-four".