21477078 has 48 divisors (see below), whose sum is σ = 55501056. Its totient is φ = 5868720.

The previous prime is 21477077. The next prime is 21477089. The reversal of 21477078 is 87077412.

It is a super-2 number, since 2×21477078² = 922529758836168, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21477077) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 808 + ... + 6603.

It is an arithmetic number, because the mean of its divisors is an integer number (1156272).

Almost surely, 2^21477078 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21477078, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27750528).

21477078 is an abundant number, since it is smaller than the sum of its proper divisors (34023978).

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

21477078 is a wasteful number, since it uses less digits than its factorization.

21477078 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7449 (or 7446 counting only the distinct ones).

The product of its (nonzero) digits is 21952, while the sum is 36.

The square root of 21477078 is about 4634.3368457634. The cubic root of 21477078 is about 277.9660345302.

The spelling of 21477078 in words is "twenty-one million, four hundred seventy-seven thousand, seventy-eight".