21375078 has 8 divisors (see below), whose sum is σ = 42750168. Its totient is φ = 7125024.

The previous prime is 21375061. The next prime is 21375097. The reversal of 21375078 is 87057312.

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

21375078 is an admirable number.

It is a Curzon number.

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, 1781251 + ... + 1781262.

It is an arithmetic number, because the mean of its divisors is an integer number (5343771).

Almost surely, 2^21375078 is an apocalyptic number.

21375078 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

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

21375078 is a wasteful number, since it uses less digits than its factorization.

21375078 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3562518.

The product of its (nonzero) digits is 11760, while the sum is 33.

The square root of 21375078 is about 4623.3189377329. The cubic root of 21375078 is about 277.5252927194.

The spelling of 21375078 in words is "twenty-one million, three hundred seventy-five thousand, seventy-eight".