81961942 has 8 divisors (see below), whose sum is σ = 123697656. Its totient is φ = 40729392.

The previous prime is 81961927. The next prime is 81961961. The reversal of 81961942 is 24916918.

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

It is a super-2 number, since 2×81961942² = 13435519872822728, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 81961895 and 81961904.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 125383 + ... + 126034.

It is an arithmetic number, because the mean of its divisors is an integer number (15462207).

Almost surely, 2^81961942 is an apocalyptic number.

81961942 is a deficient number, since it is larger than the sum of its proper divisors (41735714).

81961942 is a wasteful number, since it uses less digits than its factorization.

81961942 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 251582.

The product of its digits is 31104, while the sum is 40.

The square root of 81961942 is about 9053.2834927445. The cubic root of 81961942 is about 434.3809258685.

The spelling of 81961942 in words is "eighty-one million, nine hundred sixty-one thousand, nine hundred forty-two".