156994821 has 8 divisors (see below), whose sum is σ = 232584960. Its totient is φ = 104663196.

The previous prime is 156994793. The next prime is 156994823. The reversal of 156994821 is 128499651.

156994821 is a `hidden beast` number, since 1 + 569 + 9 + 4 + 82 + 1 = 666.

It is not a de Polignac number, because 156994821 - 2¹³ = 156986629 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (156994823) 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 7 ways as a sum of consecutive naturals, for example, 2907285 + ... + 2907338.

It is an arithmetic number, because the mean of its divisors is an integer number (29073120).

Almost surely, 2^156994821 is an apocalyptic number.

It is an amenable number.

156994821 is a deficient number, since it is larger than the sum of its proper divisors (75590139).

156994821 is an equidigital number, since it uses as much as digits as its factorization.

156994821 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5814632 (or 5814626 counting only the distinct ones).

The product of its digits is 155520, while the sum is 45.

The square root of 156994821 is about 12529.7574198386. The cubic root of 156994821 is about 539.4631392767.

The spelling of 156994821 in words is "one hundred fifty-six million, nine hundred ninety-four thousand, eight hundred twenty-one".