21270040 has 32 divisors (see below), whose sum is σ = 52209360. Its totient is φ = 7734400.

The previous prime is 21270037. The next prime is 21270071. The reversal of 21270040 is 4007212.

It is a junction number, because it is equal to n+sod(n) for n = 21269996 and 21270023.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 23731 + ... + 24610.

Almost surely, 2^21270040 is an apocalyptic number.

21270040 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21270040 is an abundant number, since it is smaller than the sum of its proper divisors (30939320).

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

21270040 is a wasteful number, since it uses less digits than its factorization.

21270040 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 48363 (or 48359 counting only the distinct ones).

The product of its (nonzero) digits is 112, while the sum is 16.

The square root of 21270040 is about 4611.9453596069. The cubic root of 21270040 is about 277.0699558745.

Adding to 21270040 its reverse (4007212), we get a palindrome (25277252).

The spelling of 21270040 in words is "twenty-one million, two hundred seventy thousand, forty".