61712121 has 4 divisors (see below), whose sum is σ = 82282832. Its totient is φ = 41141412.

The previous prime is 61712117. The next prime is 61712129. The reversal of 61712121 is 12121716.

It is a happy number.

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 not a de Polignac number, because 61712121 - 2² = 61712117 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (61712129) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 10285351 + ... + 10285356.

It is an arithmetic number, because the mean of its divisors is an integer number (20570708).

Almost surely, 2^61712121 is an apocalyptic number.

It is an amenable number.

61712121 is a deficient number, since it is larger than the sum of its proper divisors (20570711).

61712121 is a wasteful number, since it uses less digits than its factorization.

61712121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20570710.

The product of its digits is 168, while the sum is 21.

The square root of 61712121 is about 7855.7062699671. The cubic root of 61712121 is about 395.1756330522.

Adding to 61712121 its reverse (12121716), we get a palindrome (73833837).

The spelling of 61712121 in words is "sixty-one million, seven hundred twelve thousand, one hundred twenty-one".