1525421 has 2 divisors, whose sum is σ = 1525422. Its totient is φ = 1525420.

The previous prime is 1525409. The next prime is 1525423. The reversal of 1525421 is 1245251.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1525225 + 196 = 1235^2 + 14^2 .

It is a cyclic number.

It is not a de Polignac number, because 1525421 - 2⁶ = 1525357 is a prime.

Together with 1525423, it forms a pair of twin primes.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 1525393 and 1525402.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1525423) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 762710 + 762711.

It is an arithmetic number, because the mean of its divisors is an integer number (762711).

2^1525421 is an apocalyptic number.

It is an amenable number.

1525421 is a deficient number, since it is larger than the sum of its proper divisors (1).

1525421 is an equidigital number, since it uses as much as digits as its factorization.

1525421 is an evil number, because the sum of its binary digits is even.

The product of its digits is 400, while the sum is 20.

The square root of 1525421 is about 1235.0793496776. The cubic root of 1525421 is about 115.1144669961.

The spelling of 1525421 in words is "one million, five hundred twenty-five thousand, four hundred twenty-one".