747156021 has 4 divisors (see below), whose sum is σ = 996208032. Its totient is φ = 498104012.

The previous prime is 747155987. The next prime is 747156023. The reversal of 747156021 is 120651747.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 120651747 = 3 ⋅40217249.

It is a cyclic number.

It is not a de Polignac number, because 747156021 - 2¹¹ = 747153973 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (747156023) 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 3 ways as a sum of consecutive naturals, for example, 124526001 + ... + 124526006.

It is an arithmetic number, because the mean of its divisors is an integer number (249052008).

Almost surely, 2^747156021 is an apocalyptic number.

It is an amenable number.

747156021 is a deficient number, since it is larger than the sum of its proper divisors (249052011).

747156021 is a wasteful number, since it uses less digits than its factorization.

747156021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 249052010.

The product of its (nonzero) digits is 11760, while the sum is 33.

The square root of 747156021 is about 27334.1548433457. The cubic root of 747156021 is about 907.4104300339.

The spelling of 747156021 in words is "seven hundred forty-seven million, one hundred fifty-six thousand, twenty-one".