21415470 has 32 divisors (see below), whose sum is σ = 54103680. Its totient is φ = 5410080.

The previous prime is 21415469. The next prime is 21415483. The reversal of 21415470 is 7451412.

It is a self number, because there is not a number n which added to its sum of digits gives 21415470.

It is a congruent number.

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, 18216 + ... + 19355.

It is an arithmetic number, because the mean of its divisors is an integer number (1690740).

Almost surely, 2^21415470 is an apocalyptic number.

21415470 is an abundant number, since it is smaller than the sum of its proper divisors (32688210).

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

21415470 is a wasteful number, since it uses less digits than its factorization.

21415470 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 37600.

The product of its (nonzero) digits is 1120, while the sum is 24.

The square root of 21415470 is about 4627.6851664736. The cubic root of 21415470 is about 277.6999938060.

Adding to 21415470 its reverse (7451412), we get a palindrome (28866882).

The spelling of 21415470 in words is "twenty-one million, four hundred fifteen thousand, four hundred seventy".