21541401 has 12 divisors (see below), whose sum is σ = 35560512. Its totient is φ = 12309336.

The previous prime is 21541391. The next prime is 21541417. The reversal of 21541401 is 10414512.

It is not a de Polignac number, because 21541401 - 2⁶ = 21541337 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21541451) 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, 170901 + ... + 171026.

It is an arithmetic number, because the mean of its divisors is an integer number (2963376).

Almost surely, 2^21541401 is an apocalyptic number.

21541401 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

21541401 is a deficient number, since it is larger than the sum of its proper divisors (14019111).

21541401 is a wasteful number, since it uses less digits than its factorization.

21541401 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 341940 (or 341937 counting only the distinct ones).

The product of its (nonzero) digits is 160, while the sum is 18.

The square root of 21541401 is about 4641.2714852721. The cubic root of 21541401 is about 278.2432570540.

Adding to 21541401 its reverse (10414512), we get a palindrome (31955913).

It can be divided in two parts, 215 and 41401, that added together give a triangular number (41616 = T₂₈₈).

The spelling of 21541401 in words is "twenty-one million, five hundred forty-one thousand, four hundred one".