787661021 has 16 divisors (see below), whose sum is σ = 914640000. Its totient is φ = 664339968.

The previous prime is 787661009. The next prime is 787661027. The reversal of 787661021 is 120166787.

It is a cyclic number.

It is not a de Polignac number, because 787661021 - 2⁶ = 787660957 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (787661027) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 253445 + ... + 256533.

It is an arithmetic number, because the mean of its divisors is an integer number (57165000).

Almost surely, 2^787661021 is an apocalyptic number.

It is an amenable number.

787661021 is a deficient number, since it is larger than the sum of its proper divisors (126978979).

787661021 is a wasteful number, since it uses less digits than its factorization.

787661021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3668.

The product of its (nonzero) digits is 28224, while the sum is 38.

The square root of 787661021 is about 28065.2992323260. The cubic root of 787661021 is about 923.5203110531.

The spelling of 787661021 in words is "seven hundred eighty-seven million, six hundred sixty-one thousand, twenty-one".