21398773 has 8 divisors (see below), whose sum is σ = 24097536. Its totient is φ = 18825600.

The previous prime is 21398759. The next prime is 21398777. The reversal of 21398773 is 37789312.

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 21398773 - 2⁹ = 21398261 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21398777) 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, 31036 + ... + 31717.

It is an arithmetic number, because the mean of its divisors is an integer number (3012192).

Almost surely, 2^21398773 is an apocalyptic number.

It is an amenable number.

21398773 is a deficient number, since it is larger than the sum of its proper divisors (2698763).

21398773 is a wasteful number, since it uses less digits than its factorization.

21398773 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 62795.

The product of its digits is 63504, while the sum is 40.

The square root of 21398773 is about 4625.8807809973. The cubic root of 21398773 is about 277.6278035876.

The spelling of 21398773 in words is "twenty-one million, three hundred ninety-eight thousand, seven hundred seventy-three".