42696521921 has 4 divisors (see below), whose sum is σ = 45208082052. Its totient is φ = 40184961792.

The previous prime is 42696521899. The next prime is 42696521971. The reversal of 42696521921 is 12912569624.

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 30193927696 + 12502594225 = 173764^2 + 111815^2 .

It is a cyclic number.

It is not a de Polignac number, because 42696521921 - 2¹⁰ = 42696520897 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (42696521971) 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, 1255780040 + ... + 1255780073.

It is an arithmetic number, because the mean of its divisors is an integer number (11302020513).

Almost surely, 2^42696521921 is an apocalyptic number.

It is an amenable number.

42696521921 is a deficient number, since it is larger than the sum of its proper divisors (2511560131).

42696521921 is a wasteful number, since it uses less digits than its factorization.

42696521921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2511560130.

The product of its digits is 466560, while the sum is 47.

The spelling of 42696521921 in words is "forty-two billion, six hundred ninety-six million, five hundred twenty-one thousand, nine hundred twenty-one".