65421028421 has 12 divisors (see below), whose sum is σ = 76115405088. Its totient is φ = 56065299192.

The previous prime is 65421028417. The next prime is 65421028423. The reversal of 65421028421 is 12482012456.

It is not a de Polignac number, because 65421028421 - 2² = 65421028417 is a prime.

It is a super-2 number, since 2×65421028421² (a number of 22 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (65421028423) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 170960 + ... + 400086.

It is an arithmetic number, because the mean of its divisors is an integer number (6342950424).

Almost surely, 2^65421028421 is an apocalyptic number.

It is an amenable number.

65421028421 is a deficient number, since it is larger than the sum of its proper divisors (10694376667).

65421028421 is a wasteful number, since it uses less digits than its factorization.

65421028421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 234968 (or 234961 counting only the distinct ones).

The product of its (nonzero) digits is 30720, while the sum is 35.

The spelling of 65421028421 in words is "sixty-five billion, four hundred twenty-one million, twenty-eight thousand, four hundred twenty-one".