21532706 has 16 divisors (see below), whose sum is σ = 34889400. Its totient is φ = 9907968.

The previous prime is 21532697. The next prime is 21532717. The reversal of 21532706 is 60723512.

It can be written as a sum of positive squares in 4 ways, for example, as 9247681 + 12285025 = 3041^2 + 3505^2 .

It is a Harshad number since it is a multiple of its sum of digits (26).

It is a Curzon number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 9050 + ... + 11178.

Almost surely, 2^21532706 is an apocalyptic number.

21532706 is a gapful number since it is divisible by the number (26) formed by its first and last digit.

21532706 is a deficient number, since it is larger than the sum of its proper divisors (13356694).

21532706 is a wasteful number, since it uses less digits than its factorization.

21532706 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2533.

The product of its (nonzero) digits is 2520, while the sum is 26.

The square root of 21532706 is about 4640.3346862053. The cubic root of 21532706 is about 278.2058151887.

The spelling of 21532706 in words is "twenty-one million, five hundred thirty-two thousand, seven hundred six".