21401996 has 36 divisors (see below), whose sum is σ = 47056464. Its totient is φ = 8337120.

The previous prime is 21401993. The next prime is 21402013. The reversal of 21401996 is 69910412.

It is a Smith number, since the sum of its digits (32) coincides with the sum of the digits of its prime factors.

It is not an unprimeable number, because it can be changed into a prime (21401993) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 230 + ... + 6546.

It is an arithmetic number, because the mean of its divisors is an integer number (1307124).

Almost surely, 2^21401996 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21401996, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (23528232).

21401996 is an abundant number, since it is smaller than the sum of its proper divisors (25654468).

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

21401996 is a wasteful number, since it uses less digits than its factorization.

21401996 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6350 (or 6337 counting only the distinct ones).

The product of its (nonzero) digits is 3888, while the sum is 32.

The square root of 21401996 is about 4626.2291339708. The cubic root of 21401996 is about 277.6417412947.

The spelling of 21401996 in words is "twenty-one million, four hundred one thousand, nine hundred ninety-six".