21290878 has 8 divisors (see below), whose sum is σ = 36498672. Its totient is φ = 9124656.

The previous prime is 21290839. The next prime is 21290903. The reversal of 21290878 is 87809212.

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 polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 760375 + ... + 760402.

It is an arithmetic number, because the mean of its divisors is an integer number (4562334).

Almost surely, 2^21290878 is an apocalyptic number.

21290878 is a deficient number, since it is larger than the sum of its proper divisors (15207794).

21290878 is a wasteful number, since it uses less digits than its factorization.

21290878 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1520786.

The product of its (nonzero) digits is 16128, while the sum is 37.

The square root of 21290878 is about 4614.2039400096. The cubic root of 21290878 is about 277.1604070338.

The spelling of 21290878 in words is "twenty-one million, two hundred ninety thousand, eight hundred seventy-eight".