102505421 has 4 divisors (see below), whose sum is σ = 104889312. Its totient is φ = 100121532.

The previous prime is 102505397. The next prime is 102505433. The reversal of 102505421 is 124505201.

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: 124505201 = 919 ⋅135479.

It is a cyclic number.

It is not a de Polignac number, because 102505421 - 2⁶ = 102505357 is a prime.

It is a super-2 number, since 2×102505421² = 21014722668774482, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 102505393 and 102505402.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (102505451) 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, 1191881 + ... + 1191966.

It is an arithmetic number, because the mean of its divisors is an integer number (26222328).

Almost surely, 2^102505421 is an apocalyptic number.

It is an amenable number.

102505421 is a deficient number, since it is larger than the sum of its proper divisors (2383891).

102505421 is an equidigital number, since it uses as much as digits as its factorization.

102505421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2383890.

The product of its (nonzero) digits is 400, while the sum is 20.

The square root of 102505421 is about 10124.4960862257. The cubic root of 102505421 is about 468.0033314225.

The spelling of 102505421 in words is "one hundred two million, five hundred five thousand, four hundred twenty-one".