1221522045 has 16 divisors (see below), whose sum is σ = 1956508992. Its totient is φ = 650787200.

The previous prime is 1221522037. The next prime is 1221522053. The reversal of 1221522045 is 5402251221.

It is an interprime number because it is at equal distance from previous prime (1221522037) and next prime (1221522053).

It is not a de Polignac number, because 1221522045 - 2³ = 1221522037 is a prime.

It is a super-2 number, since 2×1221522045² = 2984232212841964050, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 28431 + ... + 57020.

It is an arithmetic number, because the mean of its divisors is an integer number (122281812).

Almost surely, 2^1221522045 is an apocalyptic number.

1221522045 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

1221522045 is a deficient number, since it is larger than the sum of its proper divisors (734986947).

1221522045 is an equidigital number, since it uses as much as digits as its factorization.

1221522045 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 86412.

The product of its (nonzero) digits is 1600, while the sum is 24.

The square root of 1221522045 is about 34950.2796126154. The cubic root of 1221522045 is about 1068.9739035010.

Adding to 1221522045 its reverse (5402251221), we get a palindrome (6623773266).

The spelling of 1221522045 in words is "one billion, two hundred twenty-one million, five hundred twenty-two thousand, forty-five".