55215405 has 96 divisors (see below), whose sum is σ = 121150080. Its totient is φ = 23708160.

The previous prime is 55215389. The next prime is 55215421. The reversal of 55215405 is 50451255.

It is an interprime number because it is at equal distance from previous prime (55215389) and next prime (55215421).

It is not a de Polignac number, because 55215405 - 2⁴ = 55215389 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 112210 + ... + 112700.

It is an arithmetic number, because the mean of its divisors is an integer number (1261980).

Almost surely, 2^55215405 is an apocalyptic number.

It is an amenable number.

55215405 is an abundant number, since it is smaller than the sum of its proper divisors (65934675).

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

55215405 is a wasteful number, since it uses less digits than its factorization.

55215405 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 536 (or 523 counting only the distinct ones).

The product of its (nonzero) digits is 5000, while the sum is 27.

The square root of 55215405 is about 7430.7068977319. The cubic root of 55215405 is about 380.7910690307.

The spelling of 55215405 in words is "fifty-five million, two hundred fifteen thousand, four hundred five".