61431565 has 16 divisors (see below), whose sum is σ = 79556400. Its totient is φ = 45268992.

The previous prime is 61431529. The next prime is 61431583. The reversal of 61431565 is 56513416.

It can be written as a sum of positive squares in 8 ways, for example, as 12996 + 61418569 = 114^2 + 7837^2 .

It is a cyclic number.

It is not a de Polignac number, because 61431565 - 2⁹ = 61431053 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 49371 + ... + 50599.

It is an arithmetic number, because the mean of its divisors is an integer number (4972275).

Almost surely, 2^61431565 is an apocalyptic number.

61431565 is a gapful number since it is divisible by the number (65) formed by its first and last digit.

It is an amenable number.

61431565 is a deficient number, since it is larger than the sum of its proper divisors (18124835).

61431565 is a wasteful number, since it uses less digits than its factorization.

61431565 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2016.

The product of its digits is 10800, while the sum is 31.

The square root of 61431565 is about 7837.8290999485. The cubic root of 61431565 is about 394.5758733417.

The spelling of 61431565 in words is "sixty-one million, four hundred thirty-one thousand, five hundred sixty-five".