71621549 has 2 divisors, whose sum is σ = 71621550. Its totient is φ = 71621548.

The previous prime is 71621509. The next prime is 71621567. The reversal of 71621549 is 94512617.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 47513449 + 24108100 = 6893^2 + 4910^2 .

It is a cyclic number.

It is not a de Polignac number, because 71621549 - 2⁸ = 71621293 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (71621509) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 35810774 + 35810775.

It is an arithmetic number, because the mean of its divisors is an integer number (35810775).

Almost surely, 2^71621549 is an apocalyptic number.

It is an amenable number.

71621549 is a deficient number, since it is larger than the sum of its proper divisors (1).

71621549 is an equidigital number, since it uses as much as digits as its factorization.

71621549 is an evil number, because the sum of its binary digits is even.

The product of its digits is 15120, while the sum is 35.

The square root of 71621549 is about 8462.9515536839. The cubic root of 71621549 is about 415.2865858089.

The spelling of 71621549 in words is "seventy-one million, six hundred twenty-one thousand, five hundred forty-nine".