71511949 has 2 divisors, whose sum is σ = 71511950. Its totient is φ = 71511948.

The previous prime is 71511943. The next prime is 71511959. The reversal of 71511949 is 94911517.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 62252100 + 9259849 = 7890^2 + 3043^2 .

It is a cyclic number.

It is not a de Polignac number, because 71511949 - 2⁵ = 71511917 is a prime.

It is a super-2 number, since 2×71511949² = 10227917699557202, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (71511943) 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 as a sum of consecutive naturals, namely, 35755974 + 35755975.

It is an arithmetic number, because the mean of its divisors is an integer number (35755975).

Almost surely, 2^71511949 is an apocalyptic number.

It is an amenable number.

71511949 is a deficient number, since it is larger than the sum of its proper divisors (1).

71511949 is an equidigital number, since it uses as much as digits as its factorization.

71511949 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 11340, while the sum is 37.

The square root of 71511949 is about 8456.4737923085. The cubic root of 71511949 is about 415.0746447238.

The spelling of 71511949 in words is "seventy-one million, five hundred eleven thousand, nine hundred forty-nine".