21471025 has 6 divisors (see below), whose sum is σ = 26624102. Its totient is φ = 17176800.

The previous prime is 21471019. The next prime is 21471041. The reversal of 21471025 is 52017412.

It is a happy number.

It can be written as a sum of positive squares in 3 ways, for example, as 3297856 + 18173169 = 1816^2 + 4263^2 .

It is not a de Polignac number, because 21471025 - 2¹⁵ = 21438257 is a prime.

It is a super-2 number, since 2×21471025² = 922009829101250, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21470987 and 21471005.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 429396 + ... + 429445.

Almost surely, 2^21471025 is an apocalyptic number.

21471025 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21471025 is a deficient number, since it is larger than the sum of its proper divisors (5153077).

21471025 is an equidigital number, since it uses as much as digits as its factorization.

21471025 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 858851 (or 858846 counting only the distinct ones).

The product of its (nonzero) digits is 560, while the sum is 22.

The square root of 21471025 is about 4633.6837397475. The cubic root of 21471025 is about 277.9399185241.

Adding to 21471025 its reverse (52017412), we get a palindrome (73488437).

The spelling of 21471025 in words is "twenty-one million, four hundred seventy-one thousand, twenty-five".