21203480 has 16 divisors (see below), whose sum is σ = 47707920. Its totient is φ = 8481376.

The previous prime is 21203467. The next prime is 21203503. The reversal of 21203480 is 8430212.

It is a super-2 number, since 2×21203480² = 899175128220800, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (20).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 265004 + ... + 265083.

It is an arithmetic number, because the mean of its divisors is an integer number (2981745).

Almost surely, 2^21203480 is an apocalyptic number.

21203480 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21203480 is an abundant number, since it is smaller than the sum of its proper divisors (26504440).

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

21203480 is a wasteful number, since it uses less digits than its factorization.

21203480 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 530098 (or 530094 counting only the distinct ones).

The product of its (nonzero) digits is 384, while the sum is 20.

The square root of 21203480 is about 4604.7236616327. The cubic root of 21203480 is about 276.7806436730.

Adding to 21203480 its reverse (8430212), we get a palindrome (29633692).

The spelling of 21203480 in words is "twenty-one million, two hundred three thousand, four hundred eighty".