42720656421 has 16 divisors (see below), whose sum is σ = 58839367680. Its totient is φ = 27542474160.

The previous prime is 42720656401. The next prime is 42720656479. The reversal of 42720656421 is 12465602724.

It is not a de Polignac number, because 42720656421 - 2⁶ = 42720656357 is a prime.

It is a super-2 number, since 2×42720656421² (a number of 22 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 42720656421.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (42720656401) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 25785 + ... + 293438.

It is an arithmetic number, because the mean of its divisors is an integer number (3677460480).

Almost surely, 2^42720656421 is an apocalyptic number.

It is an amenable number.

42720656421 is a deficient number, since it is larger than the sum of its proper divisors (16118711259).

42720656421 is a wasteful number, since it uses less digits than its factorization.

42720656421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 320696.

The product of its (nonzero) digits is 161280, while the sum is 39.

The spelling of 42720656421 in words is "forty-two billion, seven hundred twenty million, six hundred fifty-six thousand, four hundred twenty-one".