21430845 has 16 divisors (see below), whose sum is σ = 38099520. Its totient is φ = 11429712.

The previous prime is 21430831. The next prime is 21430847. The reversal of 21430845 is 54803412.

It is not a de Polignac number, because 21430845 - 2⁶ = 21430781 is a prime.

It is a super-2 number, since 2×21430845² = 918562234828050, 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 (21430847) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 79239 + ... + 79508.

It is an arithmetic number, because the mean of its divisors is an integer number (2381220).

Almost surely, 2^21430845 is an apocalyptic number.

It is an amenable number.

21430845 is a deficient number, since it is larger than the sum of its proper divisors (16668675).

21430845 is a wasteful number, since it uses less digits than its factorization.

21430845 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 158761 (or 158755 counting only the distinct ones).

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

The square root of 21430845 is about 4629.3460661307. The cubic root of 21430845 is about 277.7664351220.

The spelling of 21430845 in words is "twenty-one million, four hundred thirty thousand, eight hundred forty-five".