1915421 has 6 divisors (see below), whose sum is σ = 1989210. Its totient is φ = 1842176.

The previous prime is 1915411. The next prime is 1915423. The reversal of 1915421 is 1245191.

It is a happy number.

It can be written as a sum of positive squares in 3 ways, for example, as 1466521 + 448900 = 1211^2 + 670^2 .

It is a de Polignac number, because none of the positive numbers 2^k-1915421 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1915423) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 7325 + ... + 7581.

It is an arithmetic number, because the mean of its divisors is an integer number (331535).

2^1915421 is an apocalyptic number.

It is an amenable number.

1915421 is a deficient number, since it is larger than the sum of its proper divisors (73789).

1915421 is an frugal number, since it uses more digits than its factorization.

1915421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 543 (or 286 counting only the distinct ones).

The product of its digits is 360, while the sum is 23.

The square root of 1915421 is about 1383.9873554336. The cubic root of 1915421 is about 124.1904159087.

The spelling of 1915421 in words is "one million, nine hundred fifteen thousand, four hundred twenty-one".