21771470 has 16 divisors (see below), whose sum is σ = 44787168. Its totient is φ = 7464480.

The previous prime is 21771461. The next prime is 21771487. The reversal of 21771470 is 7417712.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 155441 + ... + 155580.

It is an arithmetic number, because the mean of its divisors is an integer number (2799198).

Almost surely, 2^21771470 is an apocalyptic number.

21771470 is an abundant number, since it is smaller than the sum of its proper divisors (23015698).

21771470 is a wasteful number, since it uses less digits than its factorization.

21771470 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 311035.

The product of its (nonzero) digits is 2744, while the sum is 29.

The square root of 21771470 is about 4665.9907843887. The cubic root of 21771470 is about 279.2303267113.

The spelling of 21771470 in words is "twenty-one million, seven hundred seventy-one thousand, four hundred seventy".