1205402551 has 4 divisors (see below), whose sum is σ = 1216461400. Its totient is φ = 1194343704.

The previous prime is 1205402533. The next prime is 1205402563. The reversal of 1205402551 is 1552045021.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1552045021 = 61 ⋅25443361.

It is a cyclic number.

It is not a de Polignac number, because 1205402551 - 2⁹ = 1205402039 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1205402521) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5529261 + ... + 5529478.

It is an arithmetic number, because the mean of its divisors is an integer number (304115350).

Almost surely, 2^1205402551 is an apocalyptic number.

1205402551 is a deficient number, since it is larger than the sum of its proper divisors (11058849).

1205402551 is a wasteful number, since it uses less digits than its factorization.

1205402551 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11058848.

The product of its (nonzero) digits is 2000, while the sum is 25.

The square root of 1205402551 is about 34718.9076873107. The cubic root of 1205402551 is about 1064.2509227747.

Adding to 1205402551 its reverse (1552045021), we get a palindrome (2757447572).

The spelling of 1205402551 in words is "one billion, two hundred five million, four hundred two thousand, five hundred fifty-one".