21479887 has 8 divisors (see below), whose sum is σ = 25235280. Its totient is φ = 18024960.

The previous prime is 21479881. The next prime is 21479911. The reversal of 21479887 is 78897412.

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

It is a cyclic number.

It is not a de Polignac number, because 21479887 - 2¹⁵ = 21447119 is a prime.

It is a super-2 number, since 2×21479887² = 922771091065538, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21479881) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 74962 + ... + 75247.

It is an arithmetic number, because the mean of its divisors is an integer number (3154410).

Almost surely, 2^21479887 is an apocalyptic number.

21479887 is a deficient number, since it is larger than the sum of its proper divisors (3755393).

21479887 is a wasteful number, since it uses less digits than its factorization.

21479887 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 150233.

The product of its digits is 225792, while the sum is 46.

The square root of 21479887 is about 4634.6398997117. The cubic root of 21479887 is about 277.9781524504.

It can be divided in two parts, 21479 and 887, that added together give a triangular number (22366 = T₂₁₁).

The spelling of 21479887 in words is "twenty-one million, four hundred seventy-nine thousand, eight hundred eighty-seven".