1361718721 has 4 divisors (see below), whose sum is σ = 1485511344. Its totient is φ = 1237926100.

The previous prime is 1361718697. The next prime is 1361718739. The reversal of 1361718721 is 1278171631.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 1361718721 - 2¹⁵ = 1361685953 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1361718521) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 61896295 + ... + 61896316.

It is an arithmetic number, because the mean of its divisors is an integer number (371377836).

Almost surely, 2^1361718721 is an apocalyptic number.

1361718721 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

1361718721 is a deficient number, since it is larger than the sum of its proper divisors (123792623).

1361718721 is a wasteful number, since it uses less digits than its factorization.

1361718721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 123792622.

The product of its digits is 14112, while the sum is 37.

The square root of 1361718721 is about 36901.4731548755. The cubic root of 1361718721 is about 1108.3981767905.

The spelling of 1361718721 in words is "one billion, three hundred sixty-one million, seven hundred eighteen thousand, seven hundred twenty-one".