1280916521 has 8 divisors (see below), whose sum is σ = 1377022080. Its totient is φ = 1187679888.

The previous prime is 1280916517. The next prime is 1280916557. The reversal of 1280916521 is 1256190821.

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 1280916521 - 2² = 1280916517 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1280915521) 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, 716306 + ... + 718091.

It is an arithmetic number, because the mean of its divisors is an integer number (172127760).

Almost surely, 2^1280916521 is an apocalyptic number.

It is an amenable number.

1280916521 is a deficient number, since it is larger than the sum of its proper divisors (96105559).

1280916521 is a wasteful number, since it uses less digits than its factorization.

1280916521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1434463.

The product of its (nonzero) digits is 8640, while the sum is 35.

The square root of 1280916521 is about 35789.8941183122. The cubic root of 1280916521 is about 1086.0261328044.

The spelling of 1280916521 in words is "one billion, two hundred eighty million, nine hundred sixteen thousand, five hundred twenty-one".