1276640221 has 8 divisors (see below), whose sum is σ = 1287463104. Its totient is φ = 1265848800.

The previous prime is 1276640173. The next prime is 1276640227. The reversal of 1276640221 is 1220466721.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 1276640221 - 2¹⁷ = 1276509149 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1276640227) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 77505 + ... + 92521.

It is an arithmetic number, because the mean of its divisors is an integer number (160932888).

Almost surely, 2^1276640221 is an apocalyptic number.

It is an amenable number.

1276640221 is a deficient number, since it is larger than the sum of its proper divisors (10822883).

1276640221 is a wasteful number, since it uses less digits than its factorization.

1276640221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15731.

The product of its (nonzero) digits is 8064, while the sum is 31.

The square root of 1276640221 is about 35730.1024487756. The cubic root of 1276640221 is about 1084.8162305651.

The spelling of 1276640221 in words is "one billion, two hundred seventy-six million, six hundred forty thousand, two hundred twenty-one".