1215512401 has 4 divisors (see below), whose sum is σ = 1223562304. Its totient is φ = 1207462500.

The previous prime is 1215512383. The next prime is 1215512423. The reversal of 1215512401 is 1042155121.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 1215512401 - 2¹³ = 1215504209 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1215512471) 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, 4024725 + ... + 4025026.

It is an arithmetic number, because the mean of its divisors is an integer number (305890576).

Almost surely, 2^1215512401 is an apocalyptic number.

It is an amenable number.

1215512401 is a deficient number, since it is larger than the sum of its proper divisors (8049903).

1215512401 is an equidigital number, since it uses as much as digits as its factorization.

1215512401 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8049902.

The product of its (nonzero) digits is 400, while the sum is 22.

The square root of 1215512401 is about 34864.1994171672. The cubic root of 1215512401 is about 1067.2179748481.

Adding to 1215512401 its reverse (1042155121), we get a palindrome (2257667522).

The spelling of 1215512401 in words is "one billion, two hundred fifteen million, five hundred twelve thousand, four hundred one".