215629997 has 4 divisors (see below), whose sum is σ = 235232736. Its totient is φ = 196027260.

The previous prime is 215629979. The next prime is 215630003. The reversal of 215629997 is 799926512.

It is a happy number.

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.

It is not a de Polignac number, because 215629997 - 2⁸ = 215629741 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 (215629957) 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, 9801353 + ... + 9801374.

It is an arithmetic number, because the mean of its divisors is an integer number (58808184).

Almost surely, 2^215629997 is an apocalyptic number.

It is an amenable number.

215629997 is a deficient number, since it is larger than the sum of its proper divisors (19602739).

215629997 is a wasteful number, since it uses less digits than its factorization.

215629997 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19602738.

The product of its digits is 612360, while the sum is 50.

The square root of 215629997 is about 14684.3453037580. The cubic root of 215629997 is about 599.6572088239.

The spelling of 215629997 in words is "two hundred fifteen million, six hundred twenty-nine thousand, nine hundred ninety-seven".