61815261 has 8 divisors (see below), whose sum is σ = 82456704. Its totient is φ = 41192000.

The previous prime is 61815253. The next prime is 61815263. The reversal of 61815261 is 16251816.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 61815261 - 2³ = 61815253 is a prime.

It is a super-2 number, since 2×61815261² = 7642252984996242, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (61815263) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 10636 + ... + 15386.

It is an arithmetic number, because the mean of its divisors is an integer number (10307088).

Almost surely, 2^61815261 is an apocalyptic number.

It is an amenable number.

61815261 is a deficient number, since it is larger than the sum of its proper divisors (20641443).

61815261 is a wasteful number, since it uses less digits than its factorization.

61815261 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9091.

The product of its digits is 2880, while the sum is 30.

The square root of 61815261 is about 7862.2681841820. The cubic root of 61815261 is about 395.3956639990.

The spelling of 61815261 in words is "sixty-one million, eight hundred fifteen thousand, two hundred sixty-one".