747121905 has 24 divisors (see below), whose sum is σ = 1295647080. Its totient is φ = 398269440.

The previous prime is 747121901. The next prime is 747121937. The reversal of 747121905 is 509121747.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 4613904 + 742508001 = 2148^2 + 27249^2 .

It is not a de Polignac number, because 747121905 - 2² = 747121901 is a prime.

It is a super-2 number, since 2×747121905² = 1116382281861658050, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 747121905.

It is not an unprimeable number, because it can be changed into a prime (747121901) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 178881 + ... + 183009.

It is an arithmetic number, because the mean of its divisors is an integer number (53985295).

Almost surely, 2^747121905 is an apocalyptic number.

It is an amenable number.

747121905 is a deficient number, since it is larger than the sum of its proper divisors (548525175).

747121905 is a wasteful number, since it uses less digits than its factorization.

747121905 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8161 (or 8158 counting only the distinct ones).

The product of its (nonzero) digits is 17640, while the sum is 36.

The square root of 747121905 is about 27333.5307818072. The cubic root of 747121905 is about 907.3966186903.

The spelling of 747121905 in words is "seven hundred forty-seven million, one hundred twenty-one thousand, nine hundred five".