21372026 has 16 divisors (see below), whose sum is σ = 36555624. Its totient is φ = 9283584.

The previous prime is 21372023. The next prime is 21372031. The reversal of 21372026 is 62027312.

It can be written as a sum of positive squares in 4 ways, for example, as 12075625 + 9296401 = 3475^2 + 3049^2 .

It is a junction number, because it is equal to n+sod(n) for n = 21371992 and 21372010.

It is not an unprimeable number, because it can be changed into a prime (21372023) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 23735 + ... + 24618.

Almost surely, 2^21372026 is an apocalyptic number.

21372026 is a gapful number since it is divisible by the number (26) formed by its first and last digit.

21372026 is a deficient number, since it is larger than the sum of its proper divisors (15183598).

21372026 is a wasteful number, since it uses less digits than its factorization.

21372026 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 48385.

The product of its (nonzero) digits is 1008, while the sum is 23.

The square root of 21372026 is about 4622.9888600342. The cubic root of 21372026 is about 277.5120834497.

Adding to 21372026 its reverse (62027312), we get a palindrome (83399338).

The spelling of 21372026 in words is "twenty-one million, three hundred seventy-two thousand, twenty-six".