102021540 has 24 divisors (see below), whose sum is σ = 285660480. Its totient is φ = 27205728.

The previous prime is 102021511. The next prime is 102021541. The reversal of 102021540 is 45120201.

It is a Harshad number since it is a multiple of its sum of digits (15).

It is not an unprimeable number, because it can be changed into a prime (102021541) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 850120 + ... + 850239.

It is an arithmetic number, because the mean of its divisors is an integer number (11902520).

Almost surely, 2^102021540 is an apocalyptic number.

102021540 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

102021540 is an abundant number, since it is smaller than the sum of its proper divisors (183638940).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

102021540 is a wasteful number, since it uses less digits than its factorization.

102021540 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1700371 (or 1700369 counting only the distinct ones).

The product of its (nonzero) digits is 80, while the sum is 15.

The square root of 102021540 is about 10100.5712709727. The cubic root of 102021540 is about 467.2657600503.

Adding to 102021540 its reverse (45120201), we get a palindrome (147141741).

The spelling of 102021540 in words is "one hundred two million, twenty-one thousand, five hundred forty".