102139979 has 8 divisors (see below), whose sum is σ = 104904240. Its totient is φ = 99388800.

The previous prime is 102139967. The next prime is 102139993. The reversal of 102139979 is 979931201.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-102139979 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (41).

It is not an unprimeable number, because it can be changed into a prime (102139379) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 13724 + ... + 19814.

It is an arithmetic number, because the mean of its divisors is an integer number (13113030).

Almost surely, 2^102139979 is an apocalyptic number.

102139979 is a deficient number, since it is larger than the sum of its proper divisors (2764261).

102139979 is an equidigital number, since it uses as much as digits as its factorization.

102139979 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6541.

The product of its (nonzero) digits is 30618, while the sum is 41.

The square root of 102139979 is about 10106.4325555559. The cubic root of 102139979 is about 467.4465097464.

The spelling of 102139979 in words is "one hundred two million, one hundred thirty-nine thousand, nine hundred seventy-nine".