1200421951 has 2 divisors, whose sum is σ = 1200421952. Its totient is φ = 1200421950.

The previous prime is 1200421949. The next prime is 1200421961. The reversal of 1200421951 is 1591240021.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 1200421951 - 2¹ = 1200421949 is a prime.

Together with 1200421949, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1200421961) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 600210975 + 600210976.

It is an arithmetic number, because the mean of its divisors is an integer number (600210976).

Almost surely, 2^1200421951 is an apocalyptic number.

1200421951 is a deficient number, since it is larger than the sum of its proper divisors (1).

1200421951 is an equidigital number, since it uses as much as digits as its factorization.

1200421951 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 720, while the sum is 25.

The square root of 1200421951 is about 34647.1059541775. The cubic root of 1200421951 is about 1062.7831073218.

Adding to 1200421951 its reverse (1591240021), we get a palindrome (2791661972).

The spelling of 1200421951 in words is "one billion, two hundred million, four hundred twenty-one thousand, nine hundred fifty-one".