821087745 has 16 divisors (see below), whose sum is σ = 1328503680. Its totient is φ = 432992384.

The previous prime is 821087737. The next prime is 821087779. The reversal of 821087745 is 547780128.

It is a cyclic number.

It is not a de Polignac number, because 821087745 - 2³ = 821087737 is a prime.

It is a super-3 number, since 3×821087745³ (a number of 28 digits) contains 333 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 821087697 and 821087706.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 306189 + ... + 308858.

It is an arithmetic number, because the mean of its divisors is an integer number (83031480).

Almost surely, 2^821087745 is an apocalyptic number.

It is an amenable number.

821087745 is a deficient number, since it is larger than the sum of its proper divisors (507415935).

821087745 is a wasteful number, since it uses less digits than its factorization.

821087745 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 615144.

The product of its (nonzero) digits is 125440, while the sum is 42.

The square root of 821087745 is about 28654.6286836874. The cubic root of 821087745 is about 936.4038488045.

The spelling of 821087745 in words is "eight hundred twenty-one million, eighty-seven thousand, seven hundred forty-five".