21698946 has 48 divisors (see below), whose sum is σ = 49890048. Its totient is φ = 6804000.

The previous prime is 21698933. The next prime is 21698993. The reversal of 21698946 is 64989612.

It is a happy number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 20121 + ... + 21171.

It is an arithmetic number, because the mean of its divisors is an integer number (1039376).

Almost surely, 2^21698946 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21698946, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24945024).

21698946 is an abundant number, since it is smaller than the sum of its proper divisors (28191102).

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

21698946 is a wasteful number, since it uses less digits than its factorization.

21698946 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1127 (or 1124 counting only the distinct ones).

The product of its digits is 186624, while the sum is 45.

The square root of 21698946 is about 4658.2127473957. The cubic root of 21698946 is about 278.9199292328.

The spelling of 21698946 in words is "twenty-one million, six hundred ninety-eight thousand, nine hundred forty-six".