76661989 has 4 divisors (see below), whose sum is σ = 77365420. Its totient is φ = 75958560.

The previous prime is 76661987. The next prime is 76662011. The reversal of 76661989 is 98916667.

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 23444964 + 53217025 = 4842^2 + 7295^2 .

It is a cyclic number.

It is not a de Polignac number, because 76661989 - 2¹ = 76661987 is a prime.

It is a super-2 number, since 2×76661989² = 11754121114872242, 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 (76661983) 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, 351552 + ... + 351769.

It is an arithmetic number, because the mean of its divisors is an integer number (19341355).

Almost surely, 2^76661989 is an apocalyptic number.

It is an amenable number.

76661989 is a deficient number, since it is larger than the sum of its proper divisors (703431).

76661989 is a wasteful number, since it uses less digits than its factorization.

76661989 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 703430.

The product of its digits is 979776, while the sum is 52.

The square root of 76661989 is about 8755.6832400447. The cubic root of 76661989 is about 424.8086594283.

The spelling of 76661989 in words is "seventy-six million, six hundred sixty-one thousand, nine hundred eighty-nine".