21377436 has 12 divisors (see below), whose sum is σ = 49880712. Its totient is φ = 7125808.

The previous prime is 21377417. The next prime is 21377459. The reversal of 21377436 is 63477312.

It is a tau number, because it is divible by the number of its divisors (12).

It is a junction number, because it is equal to n+sod(n) for n = 21377397 and 21377406.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 890715 + ... + 890738.

It is an arithmetic number, because the mean of its divisors is an integer number (4156726).

Almost surely, 2^21377436 is an apocalyptic number.

It is an amenable number.

21377436 is an abundant number, since it is smaller than the sum of its proper divisors (28503276).

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

21377436 is a wasteful number, since it uses less digits than its factorization.

21377436 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1781460 (or 1781458 counting only the distinct ones).

The product of its digits is 21168, while the sum is 33.

The square root of 21377436 is about 4623.5739423091. The cubic root of 21377436 is about 277.5354974475.

The spelling of 21377436 in words is "twenty-one million, three hundred seventy-seven thousand, four hundred thirty-six".