71621653 has 4 divisors (see below), whose sum is σ = 71659180. Its totient is φ = 71584128.

The previous prime is 71621633. The next prime is 71621657. The reversal of 71621653 is 35612617.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 35612617 = 2381 ⋅14957.

It can be written as a sum of positive squares in 2 ways, for example, as 32970564 + 38651089 = 5742^2 + 6217^2 .

It is a cyclic number.

It is not a de Polignac number, because 71621653 - 2⁹ = 71621141 is a prime.

It is a super-2 number, since 2×71621653² = 10259322356904818, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (71621657) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 15738 + ... + 19771.

It is an arithmetic number, because the mean of its divisors is an integer number (17914795).

Almost surely, 2^71621653 is an apocalyptic number.

It is an amenable number.

71621653 is a deficient number, since it is larger than the sum of its proper divisors (37527).

71621653 is a wasteful number, since it uses less digits than its factorization.

71621653 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 37526.

The product of its digits is 7560, while the sum is 31.

The square root of 71621653 is about 8462.9576981100. The cubic root of 71621653 is about 415.2867868182.

The spelling of 71621653 in words is "seventy-one million, six hundred twenty-one thousand, six hundred fifty-three".