15400001261 has 4 divisors (see below), whose sum is σ = 15536284572. Its totient is φ = 15263717952.

The previous prime is 15400001251. The next prime is 15400001269. The reversal of 15400001261 is 16210000451.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 6067475236 + 9332526025 = 77894^2 + 96605^2 .

It is a cyclic number.

It is not a de Polignac number, because 15400001261 - 2¹⁰ = 15400000237 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (15400001269) 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, 68141486 + ... + 68141711.

It is an arithmetic number, because the mean of its divisors is an integer number (3884071143).

Almost surely, 2^15400001261 is an apocalyptic number.

It is an amenable number.

15400001261 is a deficient number, since it is larger than the sum of its proper divisors (136283311).

15400001261 is a wasteful number, since it uses less digits than its factorization.

15400001261 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 136283310.

The product of its (nonzero) digits is 240, while the sum is 20.

The spelling of 15400001261 in words is "fifteen billion, four hundred million, one thousand, two hundred sixty-one".