781538536 has 8 divisors (see below), whose sum is σ = 1465384770. Its totient is φ = 390769264.

The previous prime is 781538521. The next prime is 781538539. The reversal of 781538536 is 635835187.

781538536 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in only one way, i.e., 749116900 + 32421636 = 27370^2 + 5694^2 .

It is a tau number, because it is divible by the number of its divisors (8).

It is a super-2 number, since 2×781538536² = 1221604966506046592, which contains 22 as substring.

It is a hoax number, since the sum of its digits (46) coincides with the sum of the digits of its distinct prime factors.

It is not an unprimeable number, because it can be changed into a prime (781538539) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 48846151 + ... + 48846166.

Almost surely, 2^781538536 is an apocalyptic number.

It is an amenable number.

781538536 is a deficient number, since it is larger than the sum of its proper divisors (683846234).

781538536 is a wasteful number, since it uses less digits than its factorization.

781538536 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 97692323 (or 97692319 counting only the distinct ones).

The product of its digits is 604800, while the sum is 46.

The square root of 781538536 is about 27956.0107311469. The cubic root of 781538536 is about 921.1212447804.

The spelling of 781538536 in words is "seven hundred eighty-one million, five hundred thirty-eight thousand, five hundred thirty-six".