1355049721 has 9 divisors (see below), whose sum is σ = 1370349199. Its totient is φ = 1339920400.

The previous prime is 1355049673. The next prime is 1355049727. The reversal of 1355049721 is 1279405531.

The square root of 1355049721 is 36811.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 915728121 + 439321600 = 30261^2 + 20960^2 .

It is a de Polignac number, because none of the positive numbers 2^k-1355049721 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1355049727) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 4822101 + ... + 4822381.

Almost surely, 2^1355049721 is an apocalyptic number.

1355049721 is the 36811-st square number.

1355049721 is the 18406-th centered octagonal number.

It is an amenable number.

1355049721 is a deficient number, since it is larger than the sum of its proper divisors (15299478).

1355049721 is an frugal number, since it uses more digits than its factorization.

1355049721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 824 (or 412 counting only the distinct ones).

The product of its (nonzero) digits is 37800, while the sum is 37.

The cubic root of 1355049721 is about 1106.5857595062.

The spelling of 1355049721 in words is "one billion, three hundred fifty-five million, forty-nine thousand, seven hundred twenty-one".