1355694621649 has 3 divisors (see below), whose sum is σ = 1355695785993. Its totient is φ = 1355693457306.

The previous prime is 1355694621647. The next prime is 1355694621653. The reversal of 1355694621649 is 9461264965531.

It is a happy number.

The square root of 1355694621649 is 1164343.

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

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is not a de Polignac number, because 1355694621649 - 2¹ = 1355694621647 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1355694621647) by changing a digit.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 582172 + ... + 1746514.

It is an arithmetic number, because the mean of its divisors is an integer number (451898595331).

Almost surely, 2^{1355694621649} is an apocalyptic number.

1355694621649 is the 1164343-rd square number.

1355694621649 is the 582172-nd centered octagonal number.

It is an amenable number.

1355694621649 is a deficient number, since it is larger than the sum of its proper divisors (1164344).

1355694621649 is an frugal number, since it uses more digits than its factorization.

1355694621649 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2328686 (or 1164343 counting only the distinct ones).

The product of its digits is 41990400, while the sum is 61.

The spelling of 1355694621649 in words is "one trillion, three hundred fifty-five billion, six hundred ninety-four million, six hundred twenty-one thousand, six hundred forty-nine".