1217921258 has 4 divisors (see below), whose sum is σ = 1826881890. Its totient is φ = 608960628.

The previous prime is 1217921251. The next prime is 1217921311. The reversal of 1217921258 is 8521297121.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 8521297121 = 431 ⋅19770991.

It can be written as a sum of positive squares in only one way, i.e., 1212223489 + 5697769 = 34817^2 + 2387^2 .

It is not an unprimeable number, because it can be changed into a prime (1217921251) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 304480313 + ... + 304480316.

Almost surely, 2^1217921258 is an apocalyptic number.

1217921258 is a deficient number, since it is larger than the sum of its proper divisors (608960632).

1217921258 is an equidigital number, since it uses as much as digits as its factorization.

1217921258 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 608960631.

The product of its digits is 20160, while the sum is 38.

The square root of 1217921258 is about 34898.7286014835. The cubic root of 1217921258 is about 1067.9225005368.

The spelling of 1217921258 in words is "one billion, two hundred seventeen million, nine hundred twenty-one thousand, two hundred fifty-eight".