21430078 has 8 divisors (see below), whose sum is σ = 32178600. Its totient is φ = 10703880.

The previous prime is 21430069. The next prime is 21430091. The reversal of 21430078 is 87003412.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2928 + ... + 7171.

It is an arithmetic number, because the mean of its divisors is an integer number (4022325).

Almost surely, 2^21430078 is an apocalyptic number.

21430078 is a deficient number, since it is larger than the sum of its proper divisors (10748522).

21430078 is a wasteful number, since it uses less digits than its factorization.

21430078 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11162.

The product of its (nonzero) digits is 1344, while the sum is 25.

The square root of 21430078 is about 4629.2632243155. The cubic root of 21430078 is about 277.7631213719.

The spelling of 21430078 in words is "twenty-one million, four hundred thirty thousand, seventy-eight".