1221025 has 27 divisors (see below), whose sum is σ = 1741611.
Its totient is φ = 848640.
The previous prime is 1221019. The next prime is 1221029. The reversal of 1221025 is 5201221.
The square root of 1221025 is 1105.
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 889249 + 331776 = 943^2 + 576^2
It is not a de Polignac number, because 1221025 - 25 = 1220993 is a prime.
It is a Harshad number since it is a multiple of its sum of digits (13).
It is a Duffinian number.
It is a junction number, because it is equal to n+sod(n) for n = 1220996 and 1221014.
It is not an unprimeable number, because it can be changed into a prime (1221029) 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, 71817 + ... + 71833.
21221025 is an apocalyptic number.
1221025 is the 1105-th square number.
1221025 is the 553-rd centered octagonal number.
It is an amenable number.
1221025 is a deficient number, since it is larger than the sum of its proper divisors (520586).
1221025 is a wasteful number, since it uses less digits than its factorization.
1221025 is an evil number, because the sum of its binary digits is even.
The sum of its prime factors is 70 (or 35 counting only the distinct ones).
The product of its (nonzero) digits is 40, while the sum is 13.
The cubic root of 1221025 is about 106.8828893097.
The spelling of 1221025 in words is "one million, two hundred twenty-one thousand, twenty-five".