103215561 has 4 divisors (see below), whose sum is σ = 137620752. Its totient is φ = 68810372.

The previous prime is 103215547. The next prime is 103215587. The reversal of 103215561 is 165512301.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 103215561 - 2¹⁴ = 103199177 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (103215521) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 17202591 + ... + 17202596.

It is an arithmetic number, because the mean of its divisors is an integer number (34405188).

Almost surely, 2^103215561 is an apocalyptic number.

It is an amenable number.

103215561 is a deficient number, since it is larger than the sum of its proper divisors (34405191).

103215561 is an equidigital number, since it uses as much as digits as its factorization.

103215561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 34405190.

The product of its (nonzero) digits is 900, while the sum is 24.

The square root of 103215561 is about 10159.5059427120. The cubic root of 103215561 is about 469.0815942102.

Adding to 103215561 its reverse (165512301), we get a palindrome (268727862).

The spelling of 103215561 in words is "one hundred three million, two hundred fifteen thousand, five hundred sixty-one".