21799776 has 24 divisors (see below), whose sum is σ = 57224664. Its totient is φ = 7266560.

The previous prime is 21799759. The next prime is 21799777. The reversal of 21799776 is 67799712.

It is a tau number, because it is divible by the number of its divisors (24).

It is a Harshad number since it is a multiple of its sum of digits (48).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21799777) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 113445 + ... + 113636.

It is an arithmetic number, because the mean of its divisors is an integer number (2384361).

Almost surely, 2^21799776 is an apocalyptic number.

It is an amenable number.

21799776 is an abundant number, since it is smaller than the sum of its proper divisors (35424888).

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

21799776 is a wasteful number, since it uses less digits than its factorization.

21799776 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 227094 (or 227086 counting only the distinct ones).

The product of its digits is 333396, while the sum is 48.

The square root of 21799776 is about 4669.0230241454. The cubic root of 21799776 is about 279.3512873187.

The spelling of 21799776 in words is "twenty-one million, seven hundred ninety-nine thousand, seven hundred seventy-six".