61212421217 has 4 divisors (see below), whose sum is σ = 61213454016. Its totient is φ = 61211388420.

The previous prime is 61212421187. The next prime is 61212421219. The reversal of 61212421217 is 71212421216.

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 61212421217 - 2¹² = 61212417121 is a prime.

It is a super-2 number, since 2×61212421217² (a number of 22 digits) contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 61212421217.

It is not an unprimeable number, because it can be changed into a prime (61212421219) 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, 421709 + ... + 547962.

It is an arithmetic number, because the mean of its divisors is an integer number (15303363504).

Almost surely, 2^61212421217 is an apocalyptic number.

It is an amenable number.

61212421217 is a deficient number, since it is larger than the sum of its proper divisors (1032799).

61212421217 is an equidigital number, since it uses as much as digits as its factorization.

61212421217 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1032798.

The product of its digits is 2688, while the sum is 29.

Subtracting 61212421217 from its reverse (71212421216), we obtain a palindrome (9999999999).

The spelling of 61212421217 in words is "sixty-one billion, two hundred twelve million, four hundred twenty-one thousand, two hundred seventeen".