21019401 has 48 divisors (see below), whose sum is σ = 34909056. Its totient is φ = 12089088.

The previous prime is 21019393. The next prime is 21019409. The reversal of 21019401 is 10491012.

It is an interprime number because it is at equal distance from previous prime (21019393) and next prime (21019409).

It is not a de Polignac number, because 21019401 - 2³ = 21019393 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21019409) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 196390 + ... + 196496.

It is an arithmetic number, because the mean of its divisors is an integer number (727272).

Almost surely, 2^21019401 is an apocalyptic number.

It is an amenable number.

21019401 is a deficient number, since it is larger than the sum of its proper divisors (13889655).

21019401 is a wasteful number, since it uses less digits than its factorization.

21019401 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 222 (or 219 counting only the distinct ones).

The product of its (nonzero) digits is 72, while the sum is 18.

The square root of 21019401 is about 4584.6920289154. The cubic root of 21019401 is about 275.9773532143.

The spelling of 21019401 in words is "twenty-one million, nineteen thousand, four hundred one".