213503991 has 16 divisors (see below), whose sum is σ = 287099904. Its totient is φ = 141128064.

The previous prime is 213503977. The next prime is 213503993. The reversal of 213503991 is 199305312.

It is not a de Polignac number, because 213503991 - 2²⁶ = 146395127 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (213503993) 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, 224980 + ... + 225926.

It is an arithmetic number, because the mean of its divisors is an integer number (17943744).

Almost surely, 2^213503991 is an apocalyptic number.

213503991 is a deficient number, since it is larger than the sum of its proper divisors (73595913).

213503991 is a wasteful number, since it uses less digits than its factorization.

213503991 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1510.

The product of its (nonzero) digits is 7290, while the sum is 33.

The square root of 213503991 is about 14611.7757647727. The cubic root of 213503991 is about 597.6799208401.

The spelling of 213503991 in words is "two hundred thirteen million, five hundred three thousand, nine hundred ninety-one".