421021540 has 24 divisors (see below), whose sum is σ = 912667392. Its totient is φ = 162975840.

The previous prime is 421021511. The next prime is 421021543. The reversal of 421021540 is 45120124.

It is not an unprimeable number, because it can be changed into a prime (421021543) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 338914 + ... + 340153.

It is an arithmetic number, because the mean of its divisors is an integer number (38027808).

Almost surely, 2^421021540 is an apocalyptic number.

It is an amenable number.

421021540 is an abundant number, since it is smaller than the sum of its proper divisors (491645852).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

421021540 is a wasteful number, since it uses less digits than its factorization.

421021540 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 679107 (or 679105 counting only the distinct ones).

The product of its (nonzero) digits is 320, while the sum is 19.

The square root of 421021540 is about 20518.8094196520. The cubic root of 421021540 is about 749.4939044925.

Adding to 421021540 its reverse (45120124), we get a palindrome (466141664).

The spelling of 421021540 in words is "four hundred twenty-one million, twenty-one thousand, five hundred forty".