1572909780649 has 3 divisors (see below), whose sum is σ = 1572911034807. Its totient is φ = 1572908526492.

The previous prime is 1572909780557. The next prime is 1572909780679. The reversal of 1572909780649 is 9460879092751.

It is a happy number.

The square root of 1572909780649 is 1254157.

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 can be written as a sum of positive squares in only one way, i.e., 476424355225 + 1096485425424 = 690235^2 + 1047132^2 .

It is not a de Polignac number, because 1572909780649 - 2⁹ = 1572909780137 is a prime.

It is a super-2 number, since 2×1572909780649² (a number of 25 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1572909780679) 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, 627079 + ... + 1881235.

It is an arithmetic number, because the mean of its divisors is an integer number (524303678269).

Almost surely, 2^{1572909780649} is an apocalyptic number.

1572909780649 is the 1254157-th square number.

1572909780649 is the 627079-th centered octagonal number.

It is an amenable number.

1572909780649 is a deficient number, since it is larger than the sum of its proper divisors (1254158).

1572909780649 is an frugal number, since it uses more digits than its factorization.

1572909780649 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2508314 (or 1254157 counting only the distinct ones).

The product of its (nonzero) digits is 68584320, while the sum is 67.

The spelling of 1572909780649 in words is "one trillion, five hundred seventy-two billion, nine hundred nine million, seven hundred eighty thousand, six hundred forty-nine".