1277948721 has 64 divisors (see below), whose sum is σ = 2115993600. Its totient is φ = 669772800.

The previous prime is 1277948677. The next prime is 1277948761. The reversal of 1277948721 is 1278497721.

It is not a de Polignac number, because 1277948721 - 2¹⁷ = 1277817649 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1277948761) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 3124365 + ... + 3124773.

It is an arithmetic number, because the mean of its divisors is an integer number (33062400).

Almost surely, 2^1277948721 is an apocalyptic number.

It is an amenable number.

1277948721 is a deficient number, since it is larger than the sum of its proper divisors (838044879).

1277948721 is a wasteful number, since it uses less digits than its factorization.

1277948721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 670.

The product of its digits is 395136, while the sum is 48.

The square root of 1277948721 is about 35748.4086498966. The cubic root of 1277948721 is about 1085.1867336302.

The spelling of 1277948721 in words is "one billion, two hundred seventy-seven million, nine hundred forty-eight thousand, seven hundred twenty-one".