156421709 has 16 divisors (see below), whose sum is σ = 170201088. Its totient is φ = 143200512.

The previous prime is 156421703. The next prime is 156421723. The reversal of 156421709 is 907124651.

156421709 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a cyclic number.

It is not a de Polignac number, because 156421709 - 2⁴ = 156421693 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (156421703) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 113744 + ... + 115110.

It is an arithmetic number, because the mean of its divisors is an integer number (10637568).

Almost surely, 2^156421709 is an apocalyptic number.

It is an amenable number.

156421709 is a deficient number, since it is larger than the sum of its proper divisors (13779379).

156421709 is a wasteful number, since it uses less digits than its factorization.

156421709 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1564.

The product of its (nonzero) digits is 15120, while the sum is 35.

The square root of 156421709 is about 12506.8664740614. The cubic root of 156421709 is about 538.8058993862.

The spelling of 156421709 in words is "one hundred fifty-six million, four hundred twenty-one thousand, seven hundred nine".