71990551 has 2 divisors, whose sum is σ = 71990552. Its totient is φ = 71990550.

The previous prime is 71990539. The next prime is 71990603. The reversal of 71990551 is 15509917.

It is a happy number.

It is a weak prime.

It is an emirp because it is prime and its reverse (15509917) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 71990551 - 2¹¹ = 71988503 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 71990551.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (71990651) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 35995275 + 35995276.

It is an arithmetic number, because the mean of its divisors is an integer number (35995276).

Almost surely, 2^71990551 is an apocalyptic number.

71990551 is a deficient number, since it is larger than the sum of its proper divisors (1).

71990551 is an equidigital number, since it uses as much as digits as its factorization.

71990551 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 14175, while the sum is 37.

The square root of 71990551 is about 8484.7245683051. The cubic root of 71990551 is about 415.9985650068.

The spelling of 71990551 in words is "seventy-one million, nine hundred ninety thousand, five hundred fifty-one".