1221407945 has 8 divisors (see below), whose sum is σ = 1466230344. Its totient is φ = 976765824.

The previous prime is 1221407903. The next prime is 1221407953. The reversal of 1221407945 is 5497041221.

It can be written as a sum of positive squares in 4 ways, for example, as 95335696 + 1126072249 = 9764^2 + 33557^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 1221407945 - 2¹² = 1221403849 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 29684 + ... + 57653.

It is an arithmetic number, because the mean of its divisors is an integer number (183278793).

Almost surely, 2^1221407945 is an apocalyptic number.

It is an amenable number.

1221407945 is a deficient number, since it is larger than the sum of its proper divisors (244822399).

1221407945 is an equidigital number, since it uses as much as digits as its factorization.

1221407945 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 90139.

The product of its (nonzero) digits is 20160, while the sum is 35.

The square root of 1221407945 is about 34948.6472556521. The cubic root of 1221407945 is about 1068.9406188730.

The spelling of 1221407945 in words is "one billion, two hundred twenty-one million, four hundred seven thousand, nine hundred forty-five".