76666221 has 12 divisors (see below), whose sum is σ = 110854848. Its totient is φ = 51057864.

The previous prime is 76666211. The next prime is 76666231. The reversal of 76666221 is 12266667.

It is an interprime number because it is at equal distance from previous prime (76666211) and next prime (76666231).

It is not a de Polignac number, because 76666221 - 2²¹ = 74569069 is a prime.

It is a super-3 number, since 3×76666221³ (a number of 25 digits) contains 333 as substring.

It is a nialpdrome in base 10.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (76666211) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 6066 + ... + 13788.

It is an arithmetic number, because the mean of its divisors is an integer number (9237904).

Almost surely, 2^76666221 is an apocalyptic number.

It is an amenable number.

76666221 is a deficient number, since it is larger than the sum of its proper divisors (34188627).

76666221 is a wasteful number, since it uses less digits than its factorization.

76666221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8832 (or 8829 counting only the distinct ones).

The product of its digits is 36288, while the sum is 36.

The square root of 76666221 is about 8755.9249083121. The cubic root of 76666221 is about 424.8164762407.

The spelling of 76666221 in words is "seventy-six million, six hundred sixty-six thousand, two hundred twenty-one".