21372546 has 16 divisors (see below), whose sum is σ = 46033344. Its totient is φ = 6576144.

The previous prime is 21372541. The next prime is 21372551. The reversal of 21372546 is 64527312.

It is an interprime number because it is at equal distance from previous prime (21372541) and next prime (21372551).

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (21372541) 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, 136926 + ... + 137081.

It is an arithmetic number, because the mean of its divisors is an integer number (2877084).

Almost surely, 2^21372546 is an apocalyptic number.

21372546 is a gapful number since it is divisible by the number (26) formed by its first and last digit.

21372546 is an abundant number, since it is smaller than the sum of its proper divisors (24660798).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21372546 is a wasteful number, since it uses less digits than its factorization.

21372546 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 274025.

The product of its digits is 10080, while the sum is 30.

The square root of 21372546 is about 4623.0451003640. The cubic root of 21372546 is about 277.5143341350.

Adding to 21372546 its reverse (64527312), we get a palindrome (85899858).

The spelling of 21372546 in words is "twenty-one million, three hundred seventy-two thousand, five hundred forty-six".