1225584057721 has 27 divisors (see below), whose sum is σ = 1261897850343. Its totient is φ = 1190311987200.

The previous prime is 1225584057701. The next prime is 1225584057743. The reversal of 1225584057721 is 1277504855221.

The square root of 1225584057721 is 1107061.

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

It can be written as a sum of positive squares in 13 ways, for example, as 755180118121 + 470403939600 = 869011^2 + 685860^2 .

It is not a de Polignac number, because 1225584057721 - 2¹⁵ = 1225584024953 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1225584057701) by changing a digit.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 10845876561 + ... + 10845876673.

Almost surely, 2^{1225584057721} is an apocalyptic number.

1225584057721 is the 1107061-st square number.

1225584057721 is the 553531-st centered octagonal number.

It is an amenable number.

1225584057721 is a deficient number, since it is larger than the sum of its proper divisors (36313792622).

1225584057721 is an frugal number, since it uses more digits than its factorization.

1225584057721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 622 (or 311 counting only the distinct ones).

The product of its (nonzero) digits is 1568000, while the sum is 49.

Multiplying 1225584057721 by its sum of digits (49), we get a square (60053618828329 = 7749427²).

The spelling of 1225584057721 in words is "one trillion, two hundred twenty-five billion, five hundred eighty-four million, fifty-seven thousand, seven hundred twenty-one".