217121231427 has 32 divisors (see below), whose sum is σ = 307637299200. Its totient is φ = 135822521088.

The previous prime is 217121231417. The next prime is 217121231429. The reversal of 217121231427 is 724132121712.

It is not a de Polignac number, because 217121231427 - 2¹¹ = 217121229379 is a prime.

It is not an unprimeable number, because it can be changed into a prime (217121231429) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 26196078 + ... + 26204364.

It is an arithmetic number, because the mean of its divisors is an integer number (9613665600).

Almost surely, 2^217121231427 is an apocalyptic number.

217121231427 is a deficient number, since it is larger than the sum of its proper divisors (90516067773).

217121231427 is a wasteful number, since it uses less digits than its factorization.

217121231427 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12635.

The product of its digits is 9408, while the sum is 33.

The spelling of 217121231427 in words is "two hundred seventeen billion, one hundred twenty-one million, two hundred thirty-one thousand, four hundred twenty-seven".