83750021 has 4 divisors (see below), whose sum is σ = 84563232. Its totient is φ = 82936812.

The previous prime is 83749993. The next prime is 83750047. The reversal of 83750021 is 12005738.

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, and also an emirpimes, since its reverse is a distinct semiprime: 12005738 = 2 ⋅6002869.

It is a cyclic number.

It is not a de Polignac number, because 83750021 - 2⁶ = 83749957 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (83750221) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 406451 + ... + 406656.

It is an arithmetic number, because the mean of its divisors is an integer number (21140808).

Almost surely, 2^83750021 is an apocalyptic number.

It is an amenable number.

83750021 is a deficient number, since it is larger than the sum of its proper divisors (813211).

83750021 is a wasteful number, since it uses less digits than its factorization.

83750021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 813210.

The product of its (nonzero) digits is 1680, while the sum is 26.

The square root of 83750021 is about 9151.5037562141. The cubic root of 83750021 is about 437.5170427102.

Adding to 83750021 its reverse (12005738), we get a palindrome (95755759).

The spelling of 83750021 in words is "eighty-three million, seven hundred fifty thousand, twenty-one".