106307721 has 20 divisors (see below), whose sum is σ = 171022852. Its totient is φ = 65419488.

The previous prime is 106307713. The next prime is 106307731. The reversal of 106307721 is 127703601.

106307721 is a `hidden beast` number, since 1 + 0 + 630 + 7 + 7 + 21 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 49154121 + 57153600 = 7011^2 + 7560^2 .

It is not a de Polignac number, because 106307721 - 2³ = 106307713 is a prime.

It is a super-2 number, since 2×106307721² = 22602663088427682, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is not an unprimeable number, because it can be changed into a prime (106307731) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 49426 + ... + 51531.

Almost surely, 2^106307721 is an apocalyptic number.

It is an amenable number.

106307721 is a deficient number, since it is larger than the sum of its proper divisors (64715131).

106307721 is a wasteful number, since it uses less digits than its factorization.

106307721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 100982 (or 100973 counting only the distinct ones).

The product of its (nonzero) digits is 1764, while the sum is 27.

The square root of 106307721 is about 10310.5635636468. The cubic root of 106307721 is about 473.7198713328.

The spelling of 106307721 in words is "one hundred six million, three hundred seven thousand, seven hundred twenty-one".