15431961 has 4 divisors (see below), whose sum is σ = 20575952. Its totient is φ = 10287972.

The previous prime is 15431959. The next prime is 15431989. The reversal of 15431961 is 16913451.

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, and also an emirpimes, since its reverse is a distinct semiprime: 16913451 = 3 ⋅5637817.

It is not a de Polignac number, because 15431961 - 2¹ = 15431959 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (15431951) 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, 2571991 + ... + 2571996.

It is an arithmetic number, because the mean of its divisors is an integer number (5143988).

Almost surely, 2^15431961 is an apocalyptic number.

It is an amenable number.

15431961 is a deficient number, since it is larger than the sum of its proper divisors (5143991).

15431961 is an equidigital number, since it uses as much as digits as its factorization.

15431961 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5143990.

The product of its digits is 3240, while the sum is 30.

The square root of 15431961 is about 3928.3534718760. The cubic root of 15431961 is about 248.9661895029.

The spelling of 15431961 in words is "fifteen million, four hundred thirty-one thousand, nine hundred sixty-one".