1561213 has 2 divisors, whose sum is σ = 1561214. Its totient is φ = 1561212.

The previous prime is 1561193. The next prime is 1561243. The reversal of 1561213 is 3121651.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1304164 + 257049 = 1142^2 + 507^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1561213 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1561243) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 780606 + 780607.

It is an arithmetic number, because the mean of its divisors is an integer number (780607).

2^1561213 is an apocalyptic number.

It is an amenable number.

1561213 is a deficient number, since it is larger than the sum of its proper divisors (1).

1561213 is an equidigital number, since it uses as much as digits as its factorization.

1561213 is an evil number, because the sum of its binary digits is even.

The product of its digits is 180, while the sum is 19.

The square root of 1561213 is about 1249.4850939487. The cubic root of 1561213 is about 116.0078522231.

Adding to 1561213 its reverse (3121651), we get a palindrome (4682864).

It can be divided in two parts, 15612 and 13, that added together give a 6-th power (15625 = 5⁶).

The spelling of 1561213 in words is "one million, five hundred sixty-one thousand, two hundred thirteen".