21101375 has 16 divisors (see below), whose sum is σ = 26487552. Its totient is φ = 16783200.

The previous prime is 21101371. The next prime is 21101383. The reversal of 21101375 is 57310112.

It is not a de Polignac number, because 21101375 - 2² = 21101371 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 (21101371) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 27497 + ... + 28253.

It is an arithmetic number, because the mean of its divisors is an integer number (1655472).

Almost surely, 2^21101375 is an apocalyptic number.

21101375 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

21101375 is a deficient number, since it is larger than the sum of its proper divisors (5386177).

21101375 is an equidigital number, since it uses as much as digits as its factorization.

21101375 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 995 (or 985 counting only the distinct ones).

The product of its (nonzero) digits is 210, while the sum is 20.

The square root of 21101375 is about 4593.6232975724. The cubic root of 21101375 is about 276.3356511164.

Adding to 21101375 its reverse (57310112), we get a palindrome (78411487).

The spelling of 21101375 in words is "twenty-one million, one hundred one thousand, three hundred seventy-five".