21375706 has 16 divisors (see below), whose sum is σ = 35080128. Its totient is φ = 9688000.

The previous prime is 21375661. The next prime is 21375721. The reversal of 21375706 is 60757312.

21375706 = 1389² + 1390² + ... + 1399².

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 7611 + ... + 10033.

It is an arithmetic number, because the mean of its divisors is an integer number (2192508).

Almost surely, 2^21375706 is an apocalyptic number.

21375706 is a deficient number, since it is larger than the sum of its proper divisors (13704422).

21375706 is a wasteful number, since it uses less digits than its factorization.

21375706 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2837.

The product of its (nonzero) digits is 8820, while the sum is 31.

The square root of 21375706 is about 4623.3868538118. The cubic root of 21375706 is about 277.5280105914.

The spelling of 21375706 in words is "twenty-one million, three hundred seventy-five thousand, seven hundred six".