1321549761 has 16 divisors (see below), whose sum is σ = 2062908288. Its totient is φ = 736752000.

The previous prime is 1321549739. The next prime is 1321549763. The reversal of 1321549761 is 1679451231.

It is not a de Polignac number, because 1321549761 - 2⁵ = 1321549729 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1321549763) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 766590 + ... + 768311.

It is an arithmetic number, because the mean of its divisors is an integer number (128931768).

Almost surely, 2^1321549761 is an apocalyptic number.

It is an amenable number.

1321549761 is a deficient number, since it is larger than the sum of its proper divisors (741358527).

1321549761 is a wasteful number, since it uses less digits than its factorization.

1321549761 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1534952.

The product of its digits is 45360, while the sum is 39.

The square root of 1321549761 is about 36353.1258766010. The cubic root of 1321549761 is about 1097.3904425519.

The spelling of 1321549761 in words is "one billion, three hundred twenty-one million, five hundred forty-nine thousand, seven hundred sixty-one".