642711421 has 4 divisors (see below), whose sum is σ = 701139744. Its totient is φ = 584283100.

The previous prime is 642711403. The next prime is 642711431. The reversal of 642711421 is 124117246.

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 642711421 - 2⁵ = 642711389 is a prime.

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 642711421.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (642711431) 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, 29214145 + ... + 29214166.

It is an arithmetic number, because the mean of its divisors is an integer number (175284936).

Almost surely, 2^642711421 is an apocalyptic number.

It is an amenable number.

642711421 is a deficient number, since it is larger than the sum of its proper divisors (58428323).

642711421 is a wasteful number, since it uses less digits than its factorization.

642711421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 58428322.

The product of its digits is 2688, while the sum is 28.

The square root of 642711421 is about 25351.7538052104. The cubic root of 642711421 is about 862.9891571282.

Adding to 642711421 its reverse (124117246), we get a palindrome (766828667).

The spelling of 642711421 in words is "six hundred forty-two million, seven hundred eleven thousand, four hundred twenty-one".