76445981 has 4 divisors (see below), whose sum is σ = 77888412. Its totient is φ = 75003552.

The previous prime is 76445953. The next prime is 76445983. The reversal of 76445981 is 18954467.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 18954467 = 7 ⋅2707781.

It can be written as a sum of positive squares in 2 ways, for example, as 50537881 + 25908100 = 7109^2 + 5090^2 .

It is a cyclic number.

It is not a de Polignac number, because 76445981 - 2⁶ = 76445917 is a prime.

It is a super-2 number, since 2×76445981² = 11687976022104722, 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 (76445983) 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, 721136 + ... + 721241.

It is an arithmetic number, because the mean of its divisors is an integer number (19472103).

Almost surely, 2^76445981 is an apocalyptic number.

It is an amenable number.

76445981 is a deficient number, since it is larger than the sum of its proper divisors (1442431).

76445981 is a wasteful number, since it uses less digits than its factorization.

76445981 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1442430.

The product of its digits is 241920, while the sum is 44.

The square root of 76445981 is about 8743.3392362415. The cubic root of 76445981 is about 424.4092942398.

The spelling of 76445981 in words is "seventy-six million, four hundred forty-five thousand, nine hundred eighty-one".