75761981 has 4 divisors (see below), whose sum is σ = 75987132. Its totient is φ = 75536832.

The previous prime is 75761971. The next prime is 75761989. The reversal of 75761981 is 18916757.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 45346756 + 30415225 = 6734^2 + 5515^2 .

It is a cyclic number.

It is not a de Polignac number, because 75761981 - 2¹⁴ = 75745597 is a prime.

It is a super-2 number, since 2×75761981² = 11479755530088722, 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 (75761989) 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, 112070 + ... + 112743.

It is an arithmetic number, because the mean of its divisors is an integer number (18996783).

Almost surely, 2^75761981 is an apocalyptic number.

It is an amenable number.

75761981 is a deficient number, since it is larger than the sum of its proper divisors (225151).

75761981 is a wasteful number, since it uses less digits than its factorization.

75761981 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 225150.

The product of its digits is 105840, while the sum is 44.

The square root of 75761981 is about 8704.1358560170. The cubic root of 75761981 is about 423.1397001628.

The spelling of 75761981 in words is "seventy-five million, seven hundred sixty-one thousand, nine hundred eighty-one".