421516440 has 128 divisors (see below), whose sum is σ = 1411128000. Its totient is φ = 111919104.

The previous prime is 421516399. The next prime is 421516441. The reversal of 421516440 is 44615124.

421516440 is a `hidden beast` number, since 4 + 2 + 15 + 1 + 644 + 0 = 666.

It is a super-2 number, since 2×421516440² = 355352218380547200, 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 (421516441) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 298456 + ... + 299864.

Almost surely, 2^421516440 is an apocalyptic number.

421516440 is a gapful number since it is divisible by the number (40) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 421516440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (705564000).

421516440 is an abundant number, since it is smaller than the sum of its proper divisors (989611560).

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

421516440 is a wasteful number, since it uses less digits than its factorization.

421516440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1706 (or 1696 counting only the distinct ones).

The product of its (nonzero) digits is 3840, while the sum is 27.

The square root of 421516440 is about 20530.8655443457. The cubic root of 421516440 is about 749.7874597746.

The spelling of 421516440 in words is "four hundred twenty-one million, five hundred sixteen thousand, four hundred forty".