61506101225221 has 4 divisors (see below), whose sum is σ = 63627001267500. Its totient is φ = 59385201182944.

The previous prime is 61506101225213. The next prime is 61506101225273. The reversal of 61506101225221 is 12252210160516.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 52053483336100 + 9452617889121 = 7214810^2 + 3074511^2 .

It is a cyclic number.

It is not a de Polignac number, because 61506101225221 - 2³ = 61506101225213 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (61506101225281) 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, 1060450021096 + ... + 1060450021153.

It is an arithmetic number, because the mean of its divisors is an integer number (15906750316875).

Almost surely, 2^{61506101225221} is an apocalyptic number.

It is an amenable number.

61506101225221 is a deficient number, since it is larger than the sum of its proper divisors (2120900042279).

61506101225221 is a wasteful number, since it uses less digits than its factorization.

61506101225221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2120900042278.

The product of its (nonzero) digits is 14400, while the sum is 34.

Adding to 61506101225221 its reverse (12252210160516), we get a palindrome (73758311385737).

The spelling of 61506101225221 in words is "sixty-one trillion, five hundred six billion, one hundred one million, two hundred twenty-five thousand, two hundred twenty-one".