1212221451 has 16 divisors (see below), whose sum is σ = 1944416000. Its totient is φ = 656239968.

The previous prime is 1212221447. The next prime is 1212221453. The reversal of 1212221451 is 1541222121.

It is not a de Polignac number, because 1212221451 - 2² = 1212221447 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (21).

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1212221453) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1518676 + ... + 1519473.

It is an arithmetic number, because the mean of its divisors is an integer number (121526000).

Almost surely, 2^1212221451 is an apocalyptic number.

1212221451 is a deficient number, since it is larger than the sum of its proper divisors (732194549).

1212221451 is a wasteful number, since it uses less digits than its factorization.

1212221451 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3038178.

The product of its digits is 320, while the sum is 21.

The square root of 1212221451 is about 34816.9707326758. The cubic root of 1212221451 is about 1066.2539546689.

Adding to 1212221451 its reverse (1541222121), we get a palindrome (2753443572).

The spelling of 1212221451 in words is "one billion, two hundred twelve million, two hundred twenty-one thousand, four hundred fifty-one".