61073991 has 12 divisors (see below), whose sum is σ = 96237960. Its totient is φ = 37014480.

The previous prime is 61073963. The next prime is 61074001. The reversal of 61073991 is 19937016.

61073991 is a `hidden beast` number, since 610 + 7 + 39 + 9 + 1 = 666.

It is not a de Polignac number, because 61073991 - 2⁷ = 61073863 is a prime.

It is a hoax number, since the sum of its digits (36) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (61073921) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 308356 + ... + 308553.

It is an arithmetic number, because the mean of its divisors is an integer number (8019830).

Almost surely, 2^61073991 is an apocalyptic number.

61073991 is a deficient number, since it is larger than the sum of its proper divisors (35163969).

61073991 is a wasteful number, since it uses less digits than its factorization.

61073991 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 616926 (or 616923 counting only the distinct ones).

The product of its (nonzero) digits is 10206, while the sum is 36.

The square root of 61073991 is about 7814.9850287764. The cubic root of 61073991 is about 393.8088154016.

The spelling of 61073991 in words is "sixty-one million, seventy-three thousand, nine hundred ninety-one".