71949921 has 4 divisors (see below), whose sum is σ = 95933232. Its totient is φ = 47966612.

The previous prime is 71949907. The next prime is 71949923. The reversal of 71949921 is 12994917.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 71949921 - 2¹¹ = 71947873 is a prime.

It is a super-2 number, since 2×71949921² = 10353582263812482, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (71949923) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 11991651 + ... + 11991656.

It is an arithmetic number, because the mean of its divisors is an integer number (23983308).

Almost surely, 2^71949921 is an apocalyptic number.

It is an amenable number.

71949921 is a deficient number, since it is larger than the sum of its proper divisors (23983311).

71949921 is a wasteful number, since it uses less digits than its factorization.

71949921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 23983310.

The product of its digits is 40824, while the sum is 42.

The square root of 71949921 is about 8482.3299275612. The cubic root of 71949921 is about 415.9202899083.

The spelling of 71949921 in words is "seventy-one million, nine hundred forty-nine thousand, nine hundred twenty-one".