654432021 has 16 divisors (see below), whose sum is σ = 970072320. Its totient is φ = 436043520.

The previous prime is 654432019. The next prime is 654432091. The reversal of 654432021 is 120234456.

654432021 is a `hidden beast` number, since 654 + 4 + 3 + 2 + 0 + 2 + 1 = 666.

It is not a de Polignac number, because 654432021 - 2¹ = 654432019 is a prime.

It is a super-2 number, since 2×654432021² = 856562540220288882, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (654432001) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 51316 + ... + 62786.

It is an arithmetic number, because the mean of its divisors is an integer number (60629520).

Almost surely, 2^654432021 is an apocalyptic number.

It is an amenable number.

654432021 is a deficient number, since it is larger than the sum of its proper divisors (315640299).

654432021 is a wasteful number, since it uses less digits than its factorization.

654432021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13593 (or 13587 counting only the distinct ones).

The product of its (nonzero) digits is 5760, while the sum is 27.

The square root of 654432021 is about 25581.8689895793. The cubic root of 654432021 is about 868.2034627662.

Adding to 654432021 its reverse (120234456), we get a palindrome (774666477).

The spelling of 654432021 in words is "six hundred fifty-four million, four hundred thirty-two thousand, twenty-one".