1221429394 has 4 divisors (see below), whose sum is σ = 1832144094. Its totient is φ = 610714696.

The previous prime is 1221429359. The next prime is 1221429409. The reversal of 1221429394 is 4939241221.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 4939241221 = 499 ⋅9898279.

It can be written as a sum of positive squares in only one way, i.e., 1046846025 + 174583369 = 32355^2 + 13213^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 305357347 + ... + 305357350.

Almost surely, 2^1221429394 is an apocalyptic number.

1221429394 is a deficient number, since it is larger than the sum of its proper divisors (610714700).

1221429394 is an equidigital number, since it uses as much as digits as its factorization.

1221429394 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 610714699.

The product of its digits is 31104, while the sum is 37.

The square root of 1221429394 is about 34948.9541188288. The cubic root of 1221429394 is about 1068.9468760162.

The spelling of 1221429394 in words is "one billion, two hundred twenty-one million, four hundred twenty-nine thousand, three hundred ninety-four".