61681905 has 24 divisors (see below), whose sum is σ = 110877312. Its totient is φ = 32896368.

The previous prime is 61681897. The next prime is 61681913. The reversal of 61681905 is 50918616.

It is an interprime number because it is at equal distance from previous prime (61681897) and next prime (61681913).

It is not a de Polignac number, because 61681905 - 2³ = 61681897 is a prime.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 61681905.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 24169 + ... + 26598.

It is an arithmetic number, because the mean of its divisors is an integer number (4619888).

Almost surely, 2^61681905 is an apocalyptic number.

It is an amenable number.

61681905 is a deficient number, since it is larger than the sum of its proper divisors (49195407).

61681905 is an equidigital number, since it uses as much as digits as its factorization.

61681905 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 50787 (or 50775 counting only the distinct ones).

The product of its (nonzero) digits is 12960, while the sum is 36.

The square root of 61681905 is about 7853.7828465014. The cubic root of 61681905 is about 395.1111261337. Note that the first 4 decimals are identical.

The spelling of 61681905 in words is "sixty-one million, six hundred eighty-one thousand, nine hundred five".