1025621 has 2 divisors, whose sum is σ = 1025622. Its totient is φ = 1025620.

The previous prime is 1025611. The next prime is 1025623. The reversal of 1025621 is 1265201.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 555025 + 470596 = 745^2 + 686^2 .

It is a cyclic number.

It is not a de Polignac number, because 1025621 - 2¹⁴ = 1009237 is a prime.

Together with 1025623, it forms a pair of twin primes.

It is a Chen prime.

It is a nialpdrome in base 16.

It is a self number, because there is not a number n which added to its sum of digits gives 1025621.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1025623) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 512810 + 512811.

It is an arithmetic number, because the mean of its divisors is an integer number (512811).

2^1025621 is an apocalyptic number.

It is an amenable number.

1025621 is a deficient number, since it is larger than the sum of its proper divisors (1).

1025621 is an equidigital number, since it uses as much as digits as its factorization.

1025621 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 120, while the sum is 17.

The square root of 1025621 is about 1012.7294801673. The cubic root of 1025621 is about 100.8468416815.

The spelling of 1025621 in words is "one million, twenty-five thousand, six hundred twenty-one".