742705921 has 16 divisors (see below), whose sum is σ = 800936640. Its totient is φ = 687234240.

The previous prime is 742705913. The next prime is 742705993. The reversal of 742705921 is 129507247.

It is a cyclic number.

It is not a de Polignac number, because 742705921 - 2³ = 742705913 is a prime.

It is a super-2 number, since 2×742705921² = 1103224170176916482, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (37).

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (742705021) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 66726 + ... + 77056.

It is an arithmetic number, because the mean of its divisors is an integer number (50058540).

Almost surely, 2^742705921 is an apocalyptic number.

It is an amenable number.

742705921 is a deficient number, since it is larger than the sum of its proper divisors (58230719).

742705921 is a wasteful number, since it uses less digits than its factorization.

742705921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10464.

The product of its (nonzero) digits is 35280, while the sum is 37.

The square root of 742705921 is about 27252.6314509260. The cubic root of 742705921 is about 905.6053136309.

The spelling of 742705921 in words is "seven hundred forty-two million, seven hundred five thousand, nine hundred twenty-one".