21542502 has 32 divisors (see below), whose sum is σ = 46006272. Its totient is φ = 6701184.

The previous prime is 21542483. The next prime is 21542537. The reversal of 21542502 is 20524512.

It is a happy number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 12123 + ... + 13785.

It is an arithmetic number, because the mean of its divisors is an integer number (1437696).

Almost surely, 2^21542502 is an apocalyptic number.

21542502 is an abundant number, since it is smaller than the sum of its proper divisors (24463770).

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

21542502 is a wasteful number, since it uses less digits than its factorization.

21542502 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1812.

The product of its (nonzero) digits is 800, while the sum is 21.

The square root of 21542502 is about 4641.3900934957. The cubic root of 21542502 is about 278.2479973927.

It can be divided in two parts, 2154 and 2502, that added together give a triangular number (4656 = T₉₆).

The spelling of 21542502 in words is "twenty-one million, five hundred forty-two thousand, five hundred two".