3987512905 has 16 divisors (see below), whose sum is σ = 4955818320. Its totient is φ = 3076399872.

The previous prime is 3987512897. The next prime is 3987512923. The reversal of 3987512905 is 5092157893.

3987512905 = 44651² + 44652².

It can be written as a sum of positive squares in 8 ways, for example, as 263218176 + 3724294729 = 16224^2 + 61027^2 .

It is a cyclic number.

It is not a de Polignac number, because 3987512905 - 2³ = 3987512897 is a prime.

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, 111487 + ... + 142843.

It is an arithmetic number, because the mean of its divisors is an integer number (309738645).

Almost surely, 2^3987512905 is an apocalyptic number.

3987512905 is the 44652-nd centered square number.

It is an amenable number.

3987512905 is a deficient number, since it is larger than the sum of its proper divisors (968305415).

3987512905 is a wasteful number, since it uses less digits than its factorization.

3987512905 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 32268.

The product of its (nonzero) digits is 680400, while the sum is 49.

The square root of 3987512905 is about 63146.7568842613. The cubic root of 3987512905 is about 1585.7474944502.

The spelling of 3987512905 in words is "three billion, nine hundred eighty-seven million, five hundred twelve thousand, nine hundred five".