61391940 has 24 divisors (see below), whose sum is σ = 171897600. Its totient is φ = 16371168.

The previous prime is 61391921. The next prime is 61391951. The reversal of 61391940 is 4919316.

61391940 is nontrivially palindromic in base 14.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 511540 + ... + 511659.

It is an arithmetic number, because the mean of its divisors is an integer number (7162400).

Almost surely, 2^61391940 is an apocalyptic number.

61391940 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

61391940 is an abundant number, since it is smaller than the sum of its proper divisors (110505660).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

61391940 is a wasteful number, since it uses less digits than its factorization.

61391940 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1023211 (or 1023209 counting only the distinct ones).

The product of its (nonzero) digits is 5832, while the sum is 33.

The square root of 61391940 is about 7835.3008876494. The cubic root of 61391940 is about 394.4910177692.

It can be divided in two parts, 6 and 1391940, that added together give a triangular number (1391946 = T₁₆₆₈).

The spelling of 61391940 in words is "sixty-one million, three hundred ninety-one thousand, nine hundred forty".