21736428 has 48 divisors (see below), whose sum is σ = 59969280. Its totient is φ = 5995584.

The previous prime is 21736417. The next prime is 21736433. The reversal of 21736428 is 82463712.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2026 + ... + 6897.

It is an arithmetic number, because the mean of its divisors is an integer number (1249360).

Almost surely, 2^21736428 is an apocalyptic number.

21736428 is a gapful number since it is divisible by the number (28) formed by its first and last digit.

It is an amenable number.

21736428 is an abundant number, since it is smaller than the sum of its proper divisors (38232852).

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

21736428 is a wasteful number, since it uses less digits than its factorization.

21736428 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8966 (or 8964 counting only the distinct ones).

The product of its digits is 16128, while the sum is 33.

The square root of 21736428 is about 4662.2342283502. The cubic root of 21736428 is about 279.0804356923.

The spelling of 21736428 in words is "twenty-one million, seven hundred thirty-six thousand, four hundred twenty-eight".