61212733921 has 4 divisors (see below), whose sum is σ = 61409559744. Its totient is φ = 61015908100.

The previous prime is 61212733913. The next prime is 61212733931. The reversal of 61212733921 is 12933721216.

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 61212733921 - 2³ = 61212733913 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (61212733931) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 98412445 + ... + 98413066.

It is an arithmetic number, because the mean of its divisors is an integer number (15352389936).

Almost surely, 2^61212733921 is an apocalyptic number.

It is an amenable number.

61212733921 is a deficient number, since it is larger than the sum of its proper divisors (196825823).

61212733921 is a wasteful number, since it uses less digits than its factorization.

61212733921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 196825822.

The product of its digits is 27216, while the sum is 37.

The spelling of 61212733921 in words is "sixty-one billion, two hundred twelve million, seven hundred thirty-three thousand, nine hundred twenty-one".