71042981 has 4 divisors (see below), whose sum is σ = 72103392. Its totient is φ = 69982572.

The previous prime is 71042977. The next prime is 71043013. The reversal of 71042981 is 18924017.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 71042981 - 2² = 71042977 is a prime.

It is a super-2 number, since 2×71042981² = 10094210298732722, 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 (71042281) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 530105 + ... + 530238.

It is an arithmetic number, because the mean of its divisors is an integer number (18025848).

Almost surely, 2^71042981 is an apocalyptic number.

It is an amenable number.

71042981 is a deficient number, since it is larger than the sum of its proper divisors (1060411).

71042981 is a wasteful number, since it uses less digits than its factorization.

71042981 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1060410.

The product of its (nonzero) digits is 4032, while the sum is 32.

The square root of 71042981 is about 8428.6998404262. The cubic root of 71042981 is about 414.1653151236.

Adding to 71042981 its reverse (18924017), we get a palindrome (89966998).

The spelling of 71042981 in words is "seventy-one million, forty-two thousand, nine hundred eighty-one".